As with sys/socket.h and struct sockaddr, most of the files including
netinet/in.h just want struct sockaddr_in or a related type, so
introduce bits/types headers for these.  POSIX specifically allows
arpa/inet.h to include netinet/in.h and I think it makes sense to
preserve that.  The definition of struct sockaddr_in had a dependence
on the definition of struct sockaddr; to avoid that, bits/sockaddr.h
grows a new macro, __SOCKADDR_DATA_SIZE, which is the declared size of
struct sockaddr.sa_data.

On Linux, some kernel headers (notably linux/in.h and linux/in6.h)
attempt to cooperate with a C library’s headers in defining types such
as struct sockaddr_in.  There is a set of macros whose names begin
with __UAPI_DEF_ that indicate that a type has already been defined.
This mechanism doesn’t actually work with the kernel headers as they
are in 5.0, as far as I can tell, but it could be made to work with
straightforward changes, so it makes sense for us to support it to the
extent we can.  To do this sensibly I need to introduce a new bits
header called bits/uapi-compat.h, with a trivial definition for
non-Linux.  This replaces the existing __USE_KERNEL_IPV6_DEFS macro.

	* bits/sockaddr.h (__SOCKADDR_DATA_SIZE): New macro.
	* sysdeps/unix/bsd/bits/sockaddr.h: Likewise.
	* sysdeps/unix/sysv/linux/m68k/bits/sockaddr.h: Likewise.
	* socket/bits/types/struct_sockaddr.h: Use __SOCKADDR_DATA_SIZE as
	array length of sa_data.

	* bits/in.h: Add multiple inclusion guard.
	(__USE_KERNEL_IPV6_DEFS): Don’t define.
	* sysdeps/unix/sysv/linux/bits/in.h: Similarly.
	(IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP): Define when not
	already defined, not conditional on __USE_KERNEL_IPV6_DEFS.

	* bits/uapi-compat.h: New file, trivial generic version.
	* sysdeps/unix/sysv/linux/bits/uapi-compat.h: New file,
	Linux-specific version which recognizes kernel header guard macros
	and defines __UAPI_DEF_* macros as appropriate.
	* misc/Makefile: Install bits/uapi-compat.h.

	* include/bits/types/in_addr_t.h, include/bits/types/in_port_t.h
	* include/bits/types/struct_in_addr.h
	* include/bits/types/struct_in6_addr.h
	* include/bits/types/struct_sockaddr_in.h
	* include/bits/types/struct_sockaddr_in6.h:
	New wrapper headers.

	* inet/bits/types/in_addr_t.h, inet/bits/types/in_port_t.h
	* inet/bits/types/struct_in_addr.h
	* inet/bits/types/struct_in6_addr.h
	* inet/bits/types/struct_sockaddr_in.h
	* inet/bits/types/struct_sockaddr_in6.h
	New single-type headers, factored out of inet/netinet/in.h.
	Add __UAPI_DEF_* conditionals where appropriate, and verify that
	all conditionalized definitions agree with the relevant
	OS-supplied header.  Use __SOCKADDR_DATA_SIZE to set size of sin_zero.
	* inet/Makefile: Install the new single-type headers.

	* inet/netinet/in.h: Include bits/uapi-compat.h.
	Define in_addr_t, in_port_t, struct in_addr, struct in6_addr,
	struct sockaddr_in, and struct sockaddr_in6 by including the
	above single-type headers, not directly.  Replace all
	__USE_KERNEL_IPV6_DEFS conditionals with appropriate __UAPI_DEF_*
	conditionals.  Add appropriate __UAPI_DEF_* conditionals around
	the definitions of the IPPROTO_* constants, the IN_CLASS
	macros, and struct ip_mreq.  Import IN_LOOPBACK macro from
	Linux 5.0 linux/in.h and verify all other conditionalized
	definitions agree with the relevant linux/ header.
	Define IPPORT_RESERVED only if not already defined, and make it a
	macro so we can tell.

	* inet/netinet/igmp.h, inet/netinet/ip.h, inet/netinet/ip_icmp.h:
	Include bits/types/struct_in_addr.h, not netinet/in.h.

	* inet/netinet/ip_icmp.h: Hoist all #includes to the top of the file.

	* inet/netinet/icmp6.h, inet/netinet/ip6.h
	* sysdeps/unix/sysv/linux/net/route.h:
	Include bits/types/struct_in6_addr.h, not netinet/in.h.

	* sysdeps/mach/hurd/net/route.h: Include bits/types.h and
	bits/types/struct_in6_addr.h, not netinet/in.h.  Use __uint16_t
	and __uint32_t instead of uint16_t and uint32_t.

	* resolv/bits/types/res_state.h: Include bits/types/struct_in_addr.h
	and bits/types/struct_sockaddr_in.h.  Forward declare struct
	sockaddr_in6.  Don’t include netinet/in.h.

	* resolv/netdb.h: Don’t include netinet/in.h.  Use socklen_t
	instead of __socklen_t.  Define IPPORT_RESERVED only if not
	already defined, with definition matching netinet/in.h.
	When __USE_MISC, include bits/sockaddr.h.
	* resolv/resolv.h: Don’t include netinet/in.h.

	* inet/tst-getni1.c, inet/tst-getni2.c
	* nss/tst-nss-files-hosts-erange.c, nss/tst-nss-files-hosts-getent.c
	* nss/tst-nss-files-hosts-multi.c, posix/tst-getaddrinfo2.c
	* resolv/tst-bug18665-tcp.c, resolv/tst-resolv-ai_idn-common.c
	* resolv/tst-resolv-canonname.c, resolv/tst-resolv-edns.c
	* resolv/tst-resolv-network.c, resolv/tst-resolv-nondecimal.c
	* resolv/tst-resolv-search.c, support/tst-support-namespace.c:
	Include netinet/in.h.
	* support/resolv_test.h: Include stdint.h, not sys/cdefs.h.

	* scripts/check-obsolete-constructs.py (HEADER_ALLOWED_INCLUDES):
	Update.

Many public headers include sys/types.h and/or stdint.h when they only
need and/or are supposed to define a small number of types from that
header.  This patch changes as many of them as practical to include
only the single-type headers for the types they are actually specified
to define, and use the impl-namespace aliases for any types they need
but are not specified to define.  In most cases, where a header has
historically used uintN_t types, I changed it to use __uintN_t types;
in a few cases I chose to have it continue to define the complete set
of those types (using <bits/stdint-uintn.h>).

After this patch, the public headers that still include sys/types.h are:
stdlib.h and sys/param.h, where removal would risk breaking far too much;
the inclusion of sys/types.h; regex.h, which is taken verbatim from
gnulib and can't include features.h directly (I'm open to better ideas);
sys/bitypes.h, which is an alternative name for sys/types.h; and
the networking headers, which will be dealt with separately.  The headers
that still include stdint.h are: inttypes.h, as required by ISO C;
elf.h and thread_db.h, see discussion of debugger interface headers below;
and, again, the networking headers will be dealt with separately.

While I was at it, I moved headers out of sysdeps where possible: If
we have only a sysdeps/generic/something.h or sysdeps/gnu/something.h,
no other sysdeps variants, it is not really system-dependent and can
be moved to the directory that installs it.  If we have both
sysdeps/generic/ and gnu/something.h, the generic version is never
used (since we support only GNUish systems these days) and can be
deleted, and the gnu-version can be moved to the directory that
installs it.  If the only copy of a bits header is in the
top-level bits directory, it is not system-dependent.

For utmp.h and utmpx.h, I think we might be able to fold their
respective bits headers into the primary headers and make them not
system-dependent at all.  The remaining variation is between
s390*-*-linux* and everything else, and it appears to me that the s390
versions of the bits headers are actually the headers that everyone
should be using.  The only difference is that the s390 headers
unconditionally use 64-bit quantities for lastlog.ll_time,
utmp{,x}.ut_tv, and utmp{,x}.ut_session, whereas the generic headers
use either 64- or 32-bit quantities depending on
__WORDSIZE_TIME64_COMPAT32.  I could be wrong, but I don’t think it
makes sense for programs with 64-bit and 32-bit time_t to have
different ideas of the layout of a structures that are copied directly
to and from a shared file on disk.  But fixing that doesn’t belong in
this patch series.

The conform tests expect utmpx.h to define time_t and suseconds_t.
These are the public names for the types of the fields of struct
timeval, and utmpx.h is required to define struct timeval, so this is
a reasonable expectation even though POSIX doesn't _explicitly_ say
it's also required to define time_t and suseconds_t.  utmp.h is not a
standard header but it makes sense for it to be as consistent with
utmpx.h as possible, especially in our implementation where
/var/log/utmp and /var/log/utmpx have the same format.

I thought I was going to need to change all of the arch-specific
bits/epoll.h headers as well as sys/epoll.h, but it turned out not to
be necessary.  I still took the opportunity to give them all multiple
inclusion guards.

I suspect we do not need as many copies of bits/fcntl.h and bits/sem.h
as we have, but that’s complicated enough that it deserves its own patchset.

The debugger interface headers are a mess and I only have so much
patience for them.  This does the bare minimum required for
thread_db.h, sys/procfs.h, and sys/user.h, which are at least
nominally cross-platform interfaces, to avoid including sys/types.h,
sys/time.h, and/or signal.h.  Exposure of sys/ucontext.h is reduced
but not eliminated.  Cross-architecture consistency should be improved.
It would be desirable to stop including stdint.h from elf.h and
thread_db.h as well, but that would involve touching dozens more
bits headers and I ran out of patience.

Git does not understand “remove file X and then rename file Y over the
top of it” very well, so the diff looks bigger than it should.

This is another partial fix for Hurd-specific bug 23088.  The headers
that are still affected by that bug are aio.h, mqueue.h, regex.h,
signal.h, stdlib.h, and sys/types.h.

	* io/ftw.h: Don't include sys/types.h.
	* misc/sys/uio.h: Don't include sys/types.h.
	Include bits/types.h, bits/types/size_t.h, and bits/types/ssize_t.h.
	* posix/spawn.h: Don't include sys/types.h.
	Include bits/types.h, bits/types/mode_t.h, and bits/types/pid_t.h.
	* rt/aio.h: Don't include sys/types.h.
	Include bits/types.h, bits/pthreadtypes.h,
	bits/types/size_t.h, and bits/types/ssize_t.h.
	* sysdeps/pthread/semaphore.h: Don't include sys/types.h.
	* sysdeps/unix/sysv/linux/bits/uio-ext.h: Use __pid_t, not pid_t.

	* sysdeps/generic/netinet/in_systm.h: Rename to
	inet/netinet/in_systm.h.  Include bits/stdint-uintn.h,
	not sys/types.h or stdint.h.
	* sysdeps/generic/netinet/ip.h: Rename to
	inet/netinet/ip.h.  Include bits/stdint-uintn.h and
	bits/endian.h, not sys/types.h.
	* sysdeps/gnu/netinet/tcp.h: Rename to
	inet/netinet/tcp.h. Include bits/stdint-uintn.h and
	bits/endian.h, not sys/types.h or stdint.h.
	* sydeps/gnu/net/if.h: Rename to socket/net/if.h.
	Don’t include sys/types.h.

	* include/net/if.h: Include socket/net/if.h, rather than
	whatever the next net/if.h on the include path is.
	* include/netinet/in_systm.h, include/netinet/ip.h
	* include/netinet/tcp.h: New trivial wrappers.

	* sysdeps/generic/net/if.h: Delete, never used.
	* sysdeps/generic/netinet/tcp.h: Delete, never used.

	* bits/utmp.h: Delete file.
        * sysdeps/gnu/bits/utmp.h: Move to bits/utmp.h.
        Add multiple include guard.
        Don’t include paths.h, sys/time.h, or sys/types.h.
        Don’t use struct timeval.
        Use __intN_t for consistency with bits/utmpx.h.
        * sysdeps/unix/sysv/linux/s390/bits/utmp.h: Add multiple include guard.
        Don’t include paths.h, sys/time.h, sys/types.h, or bits/wordsize.h.
        Don’t use struct timeval.
        Use __intN_t for consistency with bits/utmpx.h.
        Use __time64_t unconditionally for lastlog.ll_time.
        Use __int64_t unconditionally for utmp.ut_session.
        Adjust indentation and blank lines to match bits/utmp.h.

        * sysdeps/gnu/bits/utmpx.h: Move to bits/utmpx.h.
        Add multiple include guard.
        Don’t include paths.h, sys/time.h, bits/types.h, or bits/wordsize.h.
        Don’t define _PATH_UTMPX or _PATH_WTMPX.
        Don’t use struct timeval.
        Use pid_t for consistency with bits/utmp.h.
        * sysdeps/unix/sysv/linux/s390/bits/utmpx.h: Add multiple include guard.
        Don’t define _PATH_UTMPX or _PATH_WTMPX.
        Don’t include paths.h, sys/time.h, bits/types.h, or bits/wordsize.h.
        Don’t define _PATH_UTMPX or _PATH_WTMPX.
        Don’t use struct timeval.
        Use pid_t for consistency with bits/utmp.h.
        Use __int64_t unconditionally for utmpx.ut_session.

        * login/utmp.h: Don’t include sys/types.h.
        Do include paths.h, bits/types.h, bits/types/pid_t.h,
        bits/types/suseconds_t, bits/types/time_t.h, and
        bits/types/struct_timeval.h.
        Move __BEGIN_DECLS to enclose only prototypes.

        * sysdeps/gnu/utmpx.h: Move to login/utmpx.h.
        Don’t include sys/time.h.  Do include bits/types.h,
        bits/types/suseconds_t, bits/types/time_t.h, and
        bits/types/struct_timeval.h.
        When __USE_GNU, include paths.h and define _PATH_UTMPX and _PATH_WTMPX.

        * login/Makefile (headers): Add utmpx.h and bits/utmpx.h.
        (routines): Add endutxent, getutmp, getutmpx, getutxent,
        getutxid, getutxline, pututxline, setutxent, updwtmpx, and
        utmpxname.  Reorganize.
        * sysdeps/gnu/Makefile: Do not add anything to sysdep_routines
        or sysdep_headers when subdir == login.

	* sysdeps/gnu/sys/mtio.h: Move to misc/sys/mtio.h.
	Don't include sys/types.h.
	* sysdeps/gnu/Makefile: Don't add anything to sysdep_headers
	for the misc directory.
	* misc/Makefile (headers): Add sys/mtio.h.
	* include/sys/mtio.h: New wrapper.

	* elf/link.h, inet/aliases.h, misc/sys/xattr.h:
	Don't include sys/types.h.  Include bits/types/size_t.h.

	* gmon/sys/gmon.h: Don't include sys/types.h.
	* gmon/sys/profil.h: Don't include sys/types.h.
	Include bits/types/size_t.h and bits/types/struct_timeval.h.
	* io/fts.h: Don't include sys/types.h.
	Include bits/types/dev_t.h, bits/types/ino_t.h, bits/types/ino64_t.h,
	and bits/types/nlink_t.h.
	* io/sys/sendfile.h: Don't include sys/types.h.
	Include bits/types.h, bits/types/off_t.h, bits/types/size_t.h,
	and bits/types/ssize_t.h.
	* stdlib/sys/random.h: Don't include sys/types.h.
	Include bits/types/size_t.h and bits/types/ssize_t.h.

	* gmon/tst-sprofil.h: Include sys/time.h.
	* sysdeps/mach/hurd/sendfile.c: Include sys/types.h.

	* sysdeps/unix/sysv/linux/sys/epoll.h: Don’t include stdint.h
	or sys/types.h.  Do include features.h and bits/types.h.
	(union epoll_data, struct epoll_event): Use __uint32_t and
	__uint64_t for field types.

	* sysdeps/unix/sysv/linux/alpha/bits/epoll.h
	* sysdeps/unix/sysv/linux/bits/epoll.h
	* sysdeps/unix/sysv/linux/hppa/bits/epoll.h
	* sysdeps/unix/sysv/linux/mips/bits/epoll.h
	* sysdeps/unix/sysv/linux/sparc/bits/epoll.h
	* sysdeps/unix/sysv/linux/x86/bits/epoll.h:
	Add multiple inclusion guard.

	* sysdeps/unix/sysv/linux/alpha/sys/acct.h: Style fix.
	* sysdeps/unix/sysv/linux/sys/acct.h: Include features.h
	and bits/stdint-uintn.h.  Don't include sys/types.h, stdint.h,
	or bits/types/time_t.h.

	* sysdeps/unix/sysv/linux/sys/fsuid.h
	* sysdeps/unix/sysv/linux/sys/quota.h
	Include bits/types.h, not sys/types.h.

	* sysdeps/nptl/sys/procfs.h: Include features.h and bits/types.h,
	not sys/types.h.
	* sysdeps/nptl/thread_db.h: Don’t include sys/types.h.
	* sysdeps/nptl/proc_service.h: Include bits/types/pid_t.h and
	bits/types/size_t.h.

	* sysdeps/unix/sysv/linux/sys/procfs.h: Include bits/types.h and
	bits/types/struct_timeval.h, not sys/time.h or sys/types.h.

	* sysdeps/unix/sysv/linux/aarch64/bits/procfs.h: Add multiple
	inclusion guard.  Include bits/types.h.  Correct a comment.

	* sysdeps/unix/sysv/linux/alpha/bits/procfs-prregset.h:
	Add multiple inclusion guard.  Include sys/ucontext.h.

	* sysdeps/unix/sysv/linux/alpha/bits/procfs.h
	* sysdeps/unix/sysv/linux/sparc/bits/procfs.h
	Add multiple inclusion guard.  Don’t include signal.h or sys/ucontext.h.
	* sysdeps/unix/sysv/linux/ia64/bits/procfs.h:
        Add multiple inclusion guard.  Include sys/ucontext.h, not signal.h.
	* sysdeps/unix/sysv/linux/powerpc/bits/procfs.h:
        Add multiple inclusion guard.  Don’t include signal.h or
	sys/ucontext.h.  Include bits/wordsize.h and asm/elf.h.
	Adjust conditional for whether to provide various fallback
	definitions.

	* sysdeps/unix/sysv/linux/arm/bits/procfs.h
	* sysdeps/unix/sysv/linux/csky/bits/procfs.h
	* sysdeps/unix/sysv/linux/hppa/bits/procfs.h
	* sysdeps/unix/sysv/linux/m68k/bits/procfs.h
	* sysdeps/unix/sysv/linux/microblaze/bits/procfs.h
	* sysdeps/unix/sysv/linux/mips/bits/procfs.h
	* sysdeps/unix/sysv/linux/nios2/bits/procfs.h
	* sysdeps/unix/sysv/linux/riscv/bits/procfs.h
	* sysdeps/unix/sysv/linux/s390/bits/procfs.h
	* sysdeps/unix/sysv/linux/sh/bits/procfs.h
	* sysdeps/unix/sysv/linux/x86/bits/procfs.h:
        Add multiple inclusion guard.  Improve commentary.

	* sysdeps/posix/dl-fileid.h (r_file_id): Use __dev_t and __ino64_t
	for field types.

	* nss/nss.h
	* sysdeps/powerpc/sys/platform/ppc.h
	* sysdeps/unix/sysv/linux/sys/eventfd.h
	* sysdeps/unix/sysv/linux/sys/fanotify.h
	* sysdeps/unix/sysv/linux/sys/inotify.h
	* sysdeps/unix/sysv/linux/sys/raw.h
	* sysdeps/unix/sysv/linux/sys/signalfd.h:
	Include bits/types.h, not stdint.h.
	Include features.h where not already doing so.
	Use __(u)intN_t types instead of (u)intN_t types in all
	declarations.

	* sysdeps/unix/sysv/linux/powerpc/bits/powerpc.h:
	Use __uint64_t instead of uint64_t.
	* nss/tst-nss-test4.c: Include stdint.h.

	* bits/fcntl.h: Add multiple include guard.  Hoist inclusion of
	bits/types.h to top of file.
	* sysdeps/mach/hurd/bits/fcntl.h: Add multiple include guard.
	Include bits/types.h, not sys/types.h; remove redundant inclusion
	of bits/types.h in middle of file.

	* bits/sem.h: Add multiple include guard.  Include bits/types.h,
	not sys/types.h.
	* sysdeps/gnu/bits/sem.h: Likewise.
	* sysdeps/unix/sysv/linux/bits/sem.h: Likewise.
	* sysdeps/unix/sysv/linux/ia64/bits/ipc.h: Likewise.
	* sysvipc/sys/sem.h: Include bits/types/pid_t.h and
	bits/types/time_t.h.

	* resolv/bits/types/res_state.h: Include bits/types.h, not
	sys/types.h.  Use __uint32_t and __uint16_t, not uint32_t and
	uint16_t.

	* sysdeps/mach/hurd/bits/socket.h: Include bits/types.h, not
	sys/types.h.
	* sysdeps/unix/sysv/linux/bits/socket.h: Likewise.  Use __pid_t,
	__uid_t, and __gid_t, not pid_t, uid_t, and gid_t.
	* socket/sys/socket.h: Include bits/types.h, bits/types/ssize_t.h,
	and bits/types/socklen_t.h.
	* inet/htonl.c, include/htons.c: Include endian.h.
	* include/netinet/ether.h: Include bits/types/size_t.h.

	* scripts/check-obsolete-constructs.py
	(HEADER_ALLOWED_INCLUDES, SYSDEP_ALLOWED_INCLUDES): Update.

	* sysdeps/mach/hurd/i386/Makefile: Update list of xfails for
        bug 23088.

Besides the snarl of debugger/ucontext interfaces, these are the only
public headers that include signal.h.

sys/wait.h includes signal.h only for the definition of siginfo_t.
We already have a single-type header for that, so use it.  siginfo_t
contains a field whose type is uid_t, but sys/wait.h is not specified
to define uid_t, so, as is already done for pid_t, the conformance
test is modified to expect that field to have type __uid_t instead.

It is not clear what subset of the definitions from signal.h are
actually expected by historical users of sys/param.h; I’ve chosen to
take the comment at face value and cut it down to bits/signum.h, which
supplies _NSIG and all of the SIG* constants.  This requires adjusting
every copy of bits/signum.h to permit inclusion by sys/param.h as well
as signal.h.

While I was at it I moved the comment about sys/param.h being obsolete
from sysdeps/mach/hurd/bits/param.h, where it’s not likely to be seen,
to the top-level sys/param.h, and edited it to give more useful advice.

This patch partially fixes Hurd-specific bug 23088; sys/wait.h is now
conformant.

	* posix/sys/wait.h: Include bits/types/siginfo_t.h, not signal.h.
	* conform/data/sys/wait.h-data: Do not expect a definition of uid_t.

	* malloc/tst-mallocfork.c, nptl/tst-fork4.c, nptl/tst-getpid3.c
	* nptl/tst-mutex9.c, nptl/tst-rwlock12.c
	* resolv/tst-resolv-res_init-skeleton.c
	* sysdeps/unix/sysv/linux/s390/tst-ptrace-singleblock.c:
        Include signal.h.

	* nptl/tst-cancel4.c, rt/tst-mqueue1.c
	* support/tst-support_capture_subprocess.c
	* sysdeps/unix/sysv/linux/tst-align-clone.c:
	Include signal.h.  Sort includes.

	* misc/sys/param.h: Include bits/signum.h, not signal.h.
	Add comment explaining that this header is obsolete, based on
	a similar comment in Hurd bits/param.h.

	* bits/param.h: Add multiple inclusion guard and defensive #error.
	* sysdeps/mach/hurd/bits/param.h: Add multiple inclusion guard.
	Remove comment explaining that this header is obsolete (see above).
	* sysdeps/mach/i386/bits/mach/param.h: Add multiple inclusion guard.
	* sysdeps/unix/sysv/linux/bits/param.h: Add multiple inclusion guard.

	* bits/signum-generic.h, bits/signum.h
	* sysdeps/unix/bsd/bits/signum.h
	* sysdeps/unix/sysv/linux/alpha/bits/signum.h
	* sysdeps/unix/sysv/linux/bits/signum.h
	* sysdeps/unix/sysv/linux/hppa/bits/signum.h
	* sysdeps/unix/sysv/linux/mips/bits/signum.h:
	Allow inclusion by sys/param.h as well as signal.h.

	* scripts/check-obsolete-constructs.py (HEADER_ALLOWED_INCLUDES):
	Update.

        * sysdeps/mach/hurd/i386/Makefile: Remove XFAILs for sys/wait.h.

This is supposedly present for BSD compatibility, but the current
generation of BSDs is not consistent about it: FreeBSD does, OpenBSD
doesn’t, NetBSD exposes only fd_set and the FD_* macros.  Programs
that need to wait for any of multiple I/O events have several
alternatives to select nowadays, so I think it makes sense to expose
select only to programs that specifically want it.

Only a few places within our own code are affected.  A few test
programs need to include sys/select.h explicitly, as does rpc/svc.h.
sysdeps/nptl/thread_db.h needs to declare sigset_t, and
sysdeps/unix/sysv/linux/pselect.c was including sys/poll.h instead of
sys/select.h, which is probably a copy-and-paste error.  sys/socket.h
needs to forward-declare struct timespec under __USE_GNU, because
recvmmsg has a struct timespec * argument; I’m open to the possibility
of having it fully declare struct timespec.

I considered taking sys/select.h out of sys/time.h as well, but POSIX
not only explicitly allows this inclusion, it requires sys/time.h to
declare almost everything that sys/select.h declares.  It doesn’t seem
worth creating another bits header just to prevent sys/time.h from
declaring pselect, sigset_t, and struct timespec.

Not including sys/select.h from sys/types.h means that sys/types.h
also no longer defines anything from sys/time.h, and a couple of files
were relying on that.  (pthread_join_common.c should be using
clock_gettime instead of gettimeofday, but that's out of scope for
this patch series.)

	* posix/sys/types.h: Don’t include sys/select.h.
	* scripts/check-obsolete-constructs.py: Remove whitelist entry
	for sys/types.h -> sys/select.h.  Adjust commentary re
	sys/time.h -> sys/select.h.

	* socket/sys/socket.h: When __USE_GNU, forward-declare struct timespec.
	* misc/tst-fdset.c, nptl/tst-cancel4.c, scripts/check-c++-types.sh
	* sunrpc/rpc/svc.h: Include sys/select.h.
	* sysdeps/nptl/thread_db.h: Include bits/types/sigset_t.h.
	* sysdeps/unix/sysv/linux/pselect.c: Include sys/select.h,
	not sys/poll.h.
	* nptl/pthread_join_common.c, sysdeps/unix/sysv/linux/dl-vdso.h:
	Include sys/time.h.

In the course of developing earlier patches in this series I
discovered that clang’s stddef.h does not implement the __need_*
convention correctly: in C++, under some circumstances __need_NULL
will also cause a definition of nullptr_t, and when the “modules”
feature is enabled, all of the __need macros are ignored and all of
stddef.h is exposed.  (I’m not sure how to actually make either of
these things happen, I discovered the problem by reading the file.)

Worse, clang’s stdarg.h does not implement __need___va_list *at all*;
including its stdarg.h will always expose all of its definitions.

These are bugs in clang but it seems prudent to work around them, and
the simplest way to do so is to have the bits/types/ headers
introduced in the previous patch make definitions themselves, when
possible.  For size_t, ptrdiff_t, and wchar_t, we can use the
predefined macros __SIZE_TYPE__, __PTRDIFF_TYPE__, and __WCHAR_TYPE__,
when available, falling back to the old approach.  For __gnuc_va_list,
we have a whitelist of compilers known to provide __builtin_va_list,
falling back to the old approach.  NULL and va_list are defined
ab initio.

An additional complication is that we must be able to tell stddef.h
and stdarg.h _not_ to define again things we have already defined.  It
appears to me, based on inspection of clang, GCC, and icc stddef.h and
stdarg.h, that we can use the macros _SIZE_T, _PTRDIFF_T, _WCHAR_T,
_VA_LIST, and __GNUC_VA_LIST to accomplish this.

Since we are no longer relying on stdarg.h to define an
implementation-namespace alias for us, I thought it would make sense
also to stop calling it __gnuc_va_list.  The bulk of this patch is
a mechanical substitution of __va_list for __gnuc_va_list throughout
our headers.

Copyright boilerplate is added to stdlib/bits/NULL.h and stdlib/bits/types/*.h
because they now contain enough commentary and code that they could
plausibly be copyrightable.

	* stdlib/bits/NULL.h: Do not use stddef.h to define NULL.
	Define NULL ab initio if not already defined, as `((void *)0)` for C,
	and either `__null` or 0 for C++, depending on compiler support.

	* stdlib/bits/types/__va_list.h: If __builtin_va_list is known to
	be available, use it to define __va_list without including
	stdarg.h.  Otherwise use __need___va_list to request a definition
	of __gnuc_va_list and nothing else from stdarg.h, then use that to
	define __va_list.
	* stdlib/bits/types/va_list.h: Use __va_list, not __gnuc_va_list,
	to define va_list.  Improve commentary.

	* stdlib/bits/types/ptrdiff_t.h: If __PTRDIFF_TYPE__ is defined,
	use it to define ptrdiff_t without including stddef.h.  Otherwise
	use __need_ptrdiff_t to request a definition of ptrdiff_t and
	nothing else from stddef.h.  Use _PTRDIFF_T as guard macro to
	match behavior of common stddef.h implementations.
	* stdlib/bits/types/size_t.h: Similarly for size_t, with
	__SIZE_TYPE__, __need_size_t, and _SIZE_T.
	* stdlib/bits/types/wchar_t.h: Similarly for wchar_t, with
	__WCHAR_TYPE__, __need_wchar_t, and _WCHAR_T.  If __cplusplus
	is defined, do nothing; wchar_t is built-in in C++.

	* conform/data/stdio.h-data, conform/data/wchar.h-data
	* include/err.h, include/stdio.h, include/syslog.h, include/wchar.h
	* libio/bits/stdio.h, libio/bits/stdio2.h, libio/iolibio.h
	* libio/libio.h, libio/stdio.h, libio/vwprintf.c, misc/bits/syslog.h
	* misc/err.c, misc/err.h, misc/syslog.h, stdio-common/printf.h
	* sysdeps/ieee754/ldbl-opt/nldbl-compat.c
	* sysdeps/ieee754/ldbl-opt/nldbl-compat.h
	* wcsmbs/bits/wchar2.h, wcsmbs/wchar.h:
	Replace all uses of __gnuc_va_list with __va_list.

        * scripts/check-obsolete-constructs.py (HEADER_ALLOWED_INCLUDES):
        bits/NULL.h is no longer allowed to include stddef.h.

We rely on the compiler's stddef.h and stdarg.h to define size_t,
ptrdiff_t, wchar_t, NULL, and __gnuc_va_list, and to implement a
convention that allows us to request the definition of a specific one:
for instance

    #define __need_size_t
    #include <stddef.h>

is expected to define size_t but not any of the other things stddef.h
defines.

This patch hides that convention behind a set of bits/types/ headers,
which allows check-obsolete-constructs.py to verify that none of our
headers include these headers unconditionally.  (Both of them define
at least one item in the user namespace that no other header is
supposed to expose.)  It will also facilitate coping with compilers
that don’t implement the __need convention.  (That scenario is not
hypothetical, see the next patch.)

Only public headers use the new bits headers.  Non-public headers and
.c files in our codebase, that were formerly defining __need macros,
now just include stddef.h and/or stdarg.h without any __need macros.
A few files didn’t need to be including stddef.h / stdarg.h at all.

Uses of NULL in public headers that aren’t expected to define NULL
are changed to a bare 0.  bits/NULL.h is only used by headers that
are expected to define NULL.

malloc.h and printf.h were, in fact, including stddef.h and/or
stdarg.h unconditionally; they no longer do that.  This broke a few of
our test cases, which are fixed by adding appropriate inclusions to
the relevant .c files.

	* stdlib/bits/NULL.h
	* stdlib/bits/types/__va_list.h
	* stdlib/bits/types/ptrdiff_t.h
	* stdlib/bits/types/size_t.h
	* stdlib/bits/types/va_list.h
	* stdlib/bits/types/wchar_t.h:
	New headers defining a single type or macro each.
	* stdlib/Makefile: Install new headers.
	* include/bits/NULL.h
	* include/bits/types/__va_list.h
	* include/bits/types/ptrdiff_t.h
	* include/bits/types/size_t.h
	* include/bits/types/va_list.h
	* include/bits/types/wchar_t.h:
	New wrapper headers.

	* malloc/malloc.h: Don’t include stdio.h or stddef.h.
	Include bits/NULL.h, bits/types/size_t.h, bits/types/ptrdiff_t.h,
	and bits/types/FILE.h.
	* stdio-common/printf.h: Don’t include stddef.h or stdarg.h.
	Include bits/types/size_t.h, bits/types/wchar_t.h, and
	bits/types/__va_list.h.  Use __gnuc_va_list instead of va_list
	in prototypes.

	* libio/bits/types/struct_FILE.h: Include bits/types/size_t.h.
	* misc/sys/param.h: Include features.h.

	* sysvipc/sys/msg.h: Include bits/msq.h after all bits/types/ headers.
	* sysvipc/sys/sem.h: Include bits/sem.h after all bits/types/ headers.
	* sysvipc/sys/shm.h: Include bits/shm.h after all bits/types/ headers.

	* hurd/hurd/signal.h: Don’t use NULL.
	* hurd/hurd/ioctl.h: Don’t include stdarg.h.
	* hurd/hurd/userlink.h: Don’t include stddef.h.  Don’t use NULL.
	* intl/libintl.h: Don’t include stddef.h.  Don’t use NULL.

	* intl/gettext.c, intl/ngettext.c: Include stddef.h
	unconditionally.  Don’t define any __need macros first.
	Don’t include stdlib.h.

	* sysdeps/posix/sigignore.c:, sysdeps/posix/sigset.c:
	Don’t include errno.h or string.h.

	* malloc/tst-malloc-thread-fail.c: Include stddef.h.
	* malloc/tst-malloc_info.c: Include stdio.h.
	* stdio-common/tst-vfprintf-user-type.c: Include stdarg.h.
	* string/tst-cmp.c: Include stdio.h.

	* debug/wcpcpy_chk.c, iconv/loop.c, iconv/skeleton.c
	* signal/sighold.c, signal/sigrelse.c, stdio-common/tempname.c
	* sysdeps/generic/ldsodefs.h, sysdeps/nptl/libc-lock.h
	* sysdeps/nptl/libc-lockP.h, sysdeps/posix/waitid.c
	* wcsmbs/wcstol_l.c, wcsmbs/wcstoll_l.c, wcsmbs/wcstoul_l.c
	* wcsmbs/wcstoull_l.c, sysdeps/posix/sigignore.c
	* sysdeps/posix/sigset.c: Don’t define __need macros before
	including stddef.h.

	* bits/socket.h, bits/types/stack_t.h, dirent/dirent.h
	* dlfcn/dlfcn.h, gmon/sys/profil.h, grp/grp.h, gshadow/gshadow.h
        * hurd/hurd/signal.h, hurd/hurd/sigpreempt.h, iconv/gconv.h
        * include/set-hooks.h, include/stdio.h, inet/aliases.h
        * io/sys/sendfile.h, libio/stdio.h, misc/bits/types/struct_iovec.h
	* misc/search.h, misc/sys/mman.h, misc/syslog.h, posix/glob.h
	* posix/sched.h, posix/sys/types.h, posix/unistd.h
	* posix/wordexp.h, pwd/pwd.h, shadow/shadow.h, signal/signal.h
        * socket/sys/socket.h, stdlib/alloca.h, stdlib/monetary.h
	* stdlib/stdlib.h, stdlib/sys/random.h, string/string.h
	* string/strings.h, sunrpc/rpc/netdb.h
	* sysdeps/htl/bits/types/struct___pthread_attr.h
	* sysdeps/mach/hurd/bits/socket.h
	* sysdeps/unix/sysv/linux/bits/socket.h
	* sysdeps/unix/sysv/linux/bits/types/stack_t.h
	* sysdeps/unix/sysv/linux/ia64/bits/sigcontext.h
	* sysdeps/unix/sysv/linux/mips/bits/types/stack_t.h
	* sysdeps/unix/sysv/linux/scsi/sg.h
	* sysdeps/unix/sysv/linux/sys/sysctl.h
	* sysvipc/sys/msg.h, sysvipc/sys/sem.h, sysvipc/sys/shm.h
        * time/time.h, wcsmbs/uchar.h, wcsmbs/wchar.h:
	Use bits/types/size_t.h instead of __need_size_t.

	* iconv/gconv.h, iconv/iconv.h, libio/libio.h
	* stdlib/inttypes.h, stdlib/stdlib.h, wcsmbs/wchar.h:
	Use bits/types/wchar_t.h instead of __need_wchar_t.

	* libio/stdio.h, locale/locale.h, misc/sys/param.h
	* posix/sched.h, posix/unistd.h, stdlib/stdlib.h
	* string/string.h, sysdeps/unix/sysv/linux/bits/sigcontext.h
	* time/time.h, wcsmbs/wchar.h: Use bits/NULL.h instead of __need_NULL.

	* libio/stdio.h, misc/err.h: Use bits/types/__va_list.h instead
	of __need___va_list.
	* libio/stdio.h: Use bits/types/va_list.h instead of manually
	defining va_list.

	* hurd/hurd/userlink.h, misc/sys/mman.h, posix/sched.h
	* sysdeps/mach/hurd/bits/socket.h
	* sysdeps/unix/sysv/linux/ia64/bits/sigcontext.h
	* wcsmbs/wchar.h: Reorganize includes; no semantic effect.
	* stdlib/stdlib.h: Normalize format of multiple include guard.
	* sysdeps/unix/sysv/linux/bits/sigcontext.h: Annotate workarounds
	for kernel header bugs.

	* sysdeps/unix/sysv/linux/aarch64/sys/user.h
	* sysdeps/unix/sysv/linux/arm/sys/user.h
	* sysdeps/unix/sysv/linux/m68k/sys/user.h
	* sysdeps/unix/sysv/linux/microblaze/sys/user.h
	* sysdeps/unix/sysv/linux/nios2/sys/user.h
	* sysdeps/unix/sysv/linux/s390/sys/user.h
	* sysdeps/unix/sysv/linux/x86/sys/user.h
	Include features.h.

	* sysdeps/unix/sysv/linux/alpha/sys/user.h
	* sysdeps/unix/sysv/linux/ia64/sys/user.h
	* sysdeps/unix/sysv/linux/mips/sys/user.h
	* sysdeps/unix/sysv/linux/powerpc/sys/user.h
	* sysdeps/unix/sysv/linux/sh/sys/user.h
	* sysdeps/unix/sysv/linux/sparc/sys/user.h
	Include features.h and bits/types/size_t.h, in that order.
	Include kernel headers, if any, after those two.
	Don’t include stddef.h or sys/types.h.

	* scripts/check-obsolete-constructs.py
	(UNIVERSAL_ALLOWED_INCLUDES): Remove stddef.h and stdarg.h.
	(HEADER_ALLOWED_INCLUDES): Update.

The convention throughout glibc is that every public header includes
features.h directly, as its first action, and relies on features.h to
include sys/cdefs.h.  In a few places, though, it’s been done the
other way around, usually in headers that were copied from a BSD
source (where the convention is exactly the opposite).  This patch
makes all installed headers match the glibc convention.

This patch also corrects a bug in glob.h: it may declare size_t
without notifying stddef.h that it has done this, so e.g.

    #define _XOPEN_SOURCE 700
    #include <glob.h>
    #include <stddef.h>
    int dummy;

declares size_t twice, which is invalid prior to C2011.  I wasn’t able
to persuade gcc 8 to issue an error, even with -std=c89 -Wsystem-headers,
but clang is not so lenient.

	* posix/glob.h: Include features.h, not sys/cdefs.h.
	When __USE_XOPEN || USE_XOPEN2K8, include stddef.h for size_t;
	otherwise, issue an immediate #error if __SIZE_TYPE__ is not
	available. Use __gsize_t, not __size_t, as an impl-namespace
	alternative name for size_t.
	* conform/data/glob.h-data: Adjust to match.

	* inet/netinet/igmp.h, mach/lock-intern.h, misc/ar.h
	* misc/sys/auxv.h, resolv/resolv.h, socket/sys/un.h
	* sunrpc/rpc/auth_des.h, sunrpc/rpc/rpc_msg.h
	* sysdeps/generic/memcopy.h, sysdeps/generic/netinet/tcp.h
	* sysdeps/htl/pthread.h, sysdeps/mach/hurd/net/ethernet.h
	* sysdeps/mach/hurd/net/if_arp.h: Include features.h, not sys/cdefs.h.

	* scripts/check-obsolete-constructs.py (HEADER_ALLOWED_INCLUDES):
        Update.

Our installed syslog.h is a trivial wrapper around sys/syslog.h, which
is where all the actual declarations are.  This is backward from
POSIX, which specifies syslog.h and its contents, and does not specify
sys/syslog.h.  This arrangement appears to have been inherited from
some BSD-phylum C library, and probably pre-dates any standardization
of syslog.

This patch swaps the contents of syslog.h and sys/syslog.h, so that
the actual declarations appear under the standardized name.  Since it
is necessary to adjust all of syslog.h’s bits headers, I also added
multiple-include guards to those files that didn’t already have
them.  (All installed headers should have multiple-include guards,
even if they are internal and only used in one public header.  The
“never include this file directly” #error convention doesn’t protect
against including the internal header a second time after its parent
header has already been included.)

	* misc/sys/syslog.h: Exchange contents with...
	* misc/syslog.h: ...this file.  Adjust multiple-include guards.

	* include/sys/syslog.h: Exchange contents with...
	* include/syslog.h: ...this file.  Adjust multiple-include guards.

	* bits/syslog-path.h, misc/bits/syslog-ldbl.h
	* misc/bits/syslog.h: Allow inclusion by syslog.h, not sys/syslog.h.
	Add multiple-include guard where not already present.

	* scripts/check-obsolete-constructs.py (HEADER_ALLOWED_INCLUDES):
        Update.

This doesn't exactly fit the theme but as long as I'm tinkering with
sys/types.h it makes sense to go through and create single-declaration
bits/types/ headers for all of the remaining cases where we have
two or more headers declaring a public type.

The remaining uses of the original __T_defined idiom are:
__error_t_defined in files shared with gnulib, which probably has to
remain as is; ____gwchar_t_defined in inttypes.h, which may not be
necessary anymore and should be addressed separately, and
__ldiv_t_defined and __lldiv_t_defined in stdlib.h, ditto.

Our handling of LFS types is a little inconsistent: some headers
declare both off_t and off64_t (for instance) when
_LARGEFILE64_SOURCE, others will only declare off_t regardless of
_LARGEFILE64_SOURCE.  I don't know if this was intentional or not.
I am tempted to centralize responsibility for _LARGEFILE64_SOURCE as
well as _FILE_OFFSET_BITS=64 in bits/types/off_t.h (etc) so that any
header that declares off_t will automatically also declare off64_t
when _LARGEFILE64_SOURCE.

sunrpc/rpc/types.h is special, because it is included in files
compiled by the *build* compiler (cross-rpcgen-objs), and therefore it
cannot unconditionally assume bits/types headers are available.  What
I did was have it include the appropriate bits/types headers only if
including sys/types.h did not cause __BIT_TYPES_DEFINED__ to be
defined.  This will do the right thing when an installed rpc/types.h
is included by application code compiled without __USE_MISC in effect.
During the build, we rely on the fact that we compile all of our own
code with __USE_MISC in effect.  This is fragile, but should be
acceptable for code that's no longer built by default anyway.

scripts/check-obsolete-constructs.py ensures that only sys/types.h and
rpc/types.h include the bits/types/ headers that define obsolete types.

	* posix/bits/types/blkcnt64_t.h
	* posix/bits/types/blkcnt_t.h
	* posix/bits/types/blksize_t.h
	* posix/bits/types/dev_t.h
	* posix/bits/types/fsblkcnt64_t.h
	* posix/bits/types/fsblkcnt_t.h
	* posix/bits/types/fsfilcnt64_t.h
	* posix/bits/types/fsfilcnt_t.h
	* posix/bits/types/fsid_t.h
	* posix/bits/types/gid_t.h
	* posix/bits/types/id_t.h
	* posix/bits/types/ino64_t.h
	* posix/bits/types/ino_t.h
	* posix/bits/types/intptr_t.h
	* posix/bits/types/key_t.h
	* posix/bits/types/loff_t.h
	* posix/bits/types/mode_t.h
	* posix/bits/types/nlink_t.h
	* posix/bits/types/off64_t.h
	* posix/bits/types/off_t.h
	* posix/bits/types/pid_t.h
	* posix/bits/types/socklen_t.h
	* posix/bits/types/ssize_t.h
	* posix/bits/types/suseconds_t.h
	* posix/bits/types/uid_t.h
	* posix/bits/types/useconds_t.h:
        New single-declaration headers for standard types canonically
	defined by sys/types.h, sys/socket.h, or inttypes.h but also
	exposed by other headers under some circumstances.  Code moved
        from posix/sys/types.h, socket/sys/socket.h, stdlib/inttypes.h
        as appropriate.

	* posix/bits/types/uint.h
	* posix/bits/types/u_int.h
	* posix/bits/types/u_intN_t.h
	* posix/bits/types/caddr_t.h
	* posix/bits/types/daddr_t.h
	* posix/bits/types/loff_t.h
	* posix/bits/types/register_t.h:
        Similarly, but for obsolete BSD-derived types whose canonical
	home is sys/types.h.  Some of these headers define more than
	one type.

        * posix/Makefile (headers): Install the above new headers.
        Rewrap the list.
        * posix/sys/types.h: All definitions of public types now
        accomplished using the above new headers.  Consolidate
        groups of definitions controlled by the same feature
        selection macros.

        * inet/arpa/inet.h, bits/socket.h
        * sysdeps/mach/hurd/bits/socket.h
        * sysdeps/unix/sysv/linux/bits/socket.h:
        Use bits/types/socklen_t.h.

        * dirent/dirent.h: Use bits/types/ino_t.h and bits/types/ino64_t.h.
        * grp/grp.h: Use bits/types/gid_t.h.
        * io/fcntl.h: Use bits/types/mode_t.h, bits/types/off_t.h,
        bits/types/pid_t.h, and bits/types/off64_t.h.
        * io/sys/stat.h: Use bits/types/dev_t.h, bits/types/gid_t.h,
        bits/types/ino_t.h, bits/types/mode_t.h, bits/types/nlink_t.h,
        bits/types/off_t.h, bits/types/uid_t.h, and bits/types/blkcnt_t.h.
        * libio/stdio.h: Use bits/types/off_t.h, bits/types/off64_t.h,
        and bits/types/ssize_t.h.
        * misc/sys/mman.h: Use bits/types/off_t.h and bits/types/mode_t.h.
        * misc/sys/select.h: Use bits/types/suseconds_t.h.
        * posix/sched.h: Use bits/types/pid_t.h.
        * posix/sys/wait.h: Use bits/types/pid_t.h and bits/types/id_t.h.
        * posix/unistd.h: Use bits/types/gid_t.h, bits/types/uid_t.h,
        bits/types/off_t.h, bits/types/off64_t.h, bits/types/useconds_t.h,
        bits/types/intptr_t.h, and bits/types/socklen_t.h.
        * pwd/pwd.h: Use bits/types/gid_t.h and bits/types/uid_t.h.
        * resource/sys/resource.h: Use bits/types/id_t.h.
        * signal/signal.h: Use bits/types/pid_t.h and bits/types/uid_t.h.
        * stdlib/monetary.h: Use bits/types/ssize_t.h.
        * sysdeps/gnu/utmpx.h: Use bits/types/pid_t.h.
        * sysvipc/sys/ipc.h: Use bits/types/uid_t.h, bits/types/gid_t.h,
        bits/types/mode_t.h, and bits/types/key_t.h.
        * sysvipc/sys/msg.h: Use bits/types/pid_t.h and bits/types/ssize_t.h.
        * sysvipc/sys/shm.h: Use bits/types/pid_t.h.
        * termios/termios.h: Use bits/types/pid_t.h.
        * time/sys/time.h: Use bits/types/suseconds_t.h.
        * time/time.h: Use bits/types/pid_t.h.

        * sunrpc/rpc/types.h: Consolidate all #includes at the top of
        the file.  If __BIT_TYPES_DEFINED__ is not defined after
        including sys/types.h, also include bits/types/caddr_t.h,
        bits/types/daddr_t.h, bits/types/fsid_t.h, and bits/types/u_int.h.

        * scripts/check-obsolete-constructs.py (OBSOLETE_TYPE_HDR_RE_): New.
        (ObsoleteIndirectDefinitionsAllowed): New; allows inclusion of
        bits/types/ headers that define obsolete typedefs, but not
        direct definitions of those types.
        (ObsoleteNotAllowed, ObsoletePrivateDefinitionsAllowed)
        (ObsoletePublicDefinitionsAllowed): Do not allow inclusion of
        bits/types/ headers that define obsolete typedefs.

	* include/bits/types/blkcnt64_t.h
	* include/bits/types/blkcnt_t.h
	* include/bits/types/blksize_t.h
	* include/bits/types/caddr_t.h
	* include/bits/types/daddr_t.h
	* include/bits/types/dev_t.h
	* include/bits/types/fsblkcnt64_t.h
	* include/bits/types/fsblkcnt_t.h
	* include/bits/types/fsfilcnt64_t.h
	* include/bits/types/fsfilcnt_t.h
	* include/bits/types/fsid_t.h
	* include/bits/types/gid_t.h
	* include/bits/types/id_t.h
	* include/bits/types/ino64_t.h
	* include/bits/types/ino_t.h
	* include/bits/types/intptr_t.h
	* include/bits/types/key_t.h
	* include/bits/types/loff_t.h
	* include/bits/types/mode_t.h
	* include/bits/types/nlink_t.h
	* include/bits/types/off64_t.h
	* include/bits/types/off_t.h
	* include/bits/types/pid_t.h
	* include/bits/types/register_t.h
	* include/bits/types/socklen_t.h
	* include/bits/types/ssize_t.h
	* include/bits/types/suseconds_t.h
	* include/bits/types/u_char.h
	* include/bits/types/u_intN_t.h
	* include/bits/types/uchar.h
	* include/bits/types/uid_t.h
	* include/bits/types/useconds_t.h: New wrappers.

caddr_t is a BSD-derived alias for ‘char *’, obsoleted by the
introduction of ‘void *’ in C89 (!)  daddr_t is a “disk address,”
but it’s always defined as ‘int’, making it too small for modern
disks and tapes.  loff_t is another name for off64_t, from early
drafts of LFS.  All three are already only exposed by sys/types.h
under __USE_MISC.

This patch adds them to the set of types that shall not be used in
installed headers (enforced by check-obsolete-constructs.py) and
expunges all remaining uses, internally as well as in installed
headers.  Since __DADDR_T_TYPE is always defined as __S32_TYPE, and
daddr_t is obsolete so there’s no need to worry about future
variation, the patch also removes __DADDR_T_TYPE from the set of
macros that bits/typesizes.h is required to define.  Instead
bits/types.h always defines __daddr_t as __S32_TYPE, and the
definition is moved to a more logical location within the file, next
to __caddr_t.

It’s always safe to change (__)loff_t to the matching (__)off64_t;
in a few internal files, I removed an unnecessary __ prefix.

daddr_t is only used for struct ustat, which is obsoleted by struct
statvfs and we already don’t declare it in public headers, and for an
ioctl parameter block in sys/mtio.h (which may or may not be obsolete,
I can’t tell).  In sys/mtio.h I replaced both uses with ‘int’ to match
the use of bare ‘long int’ for most of the other fields of that
structure.  In misc/ustat.c, the definition of struct ustat is not
actually necessary so I removed it entirely.  In
sysdeps/unix/sysv/linux/ustat.c a definition is necessary but only
because INLINE_SYSCALL_CALL doesn’t work (on at least x86) when an
argument is a pointer to an incomplete type, so I substituted a dummy
definition.

Most of the internal uses of caddr_t are in the sunrpc and nis
directories, and since most of that code is obsolete, I mechanically
replaced them with char * rather than consider whether void * might
make more sense.  Because “const caddr_t foo” is semantically
different from “const char *foo” (in the first case ‘foo’ itself is
const but the memory pointed to isn’t, in the second case the memory
pointed to is const but ‘foo’ isn’t) this change exposed some
const-correctness errors in sunrpc, which I fixed minimally.  Outside
of sunrpc and nis, I put a little more thought into whether uses of
caddr_t should be void * instead.

	* scripts/check-obsolete-constructs.py: Add caddr_t, daddr_t,
        and loff_t to the set of obsolete types forbidden in public
        headers.

	* posix/bits/types.h: Unconditionally define __daddr_t as
        __S32_TYPE.  Move definition of __daddr_t next to definition
        of __caddr_t.
	* bits/typesizes.h
	* sysdeps/mach/hurd/bits/typesizes.h
	* sysdeps/unix/sysv/linux/alpha/bits/typesizes.h
	* sysdeps/unix/sysv/linux/generic/bits/typesizes.h
	* sysdeps/unix/sysv/linux/mips/bits/typesizes.h
	* sysdeps/unix/sysv/linux/s390/bits/typesizes.h
	* sysdeps/unix/sysv/linux/sparc/bits/typesizes.h
	* sysdeps/unix/sysv/linux/x86/bits/typesizes.h:
        Don’t define __DADDR_T_TYPE.

        * sysdeps/gnu/sys/mtio.h (struct mtget): Change all uses of
	__daddr_t to int.
	* misc/ustat.c: Remove definition of struct ustat; only
        forward-declare it.
	* sysdeps/unix/sysv/linux/ustat.c: Replace fields of
        struct ustat with a size-preserving dummy field.

	* hurd/Makefile (migheaderpipe): Rewrite loff_t as __off64_t.
        * hurd/fd-read.c (_hurd_fd_read): Use off64_t instead of loff_t.
        * hurd/fd-write.c (hurd_fd_write): Use off64_t instead of loff_t.
        * hurd/hurd/fd.h (_hurd_fd_read, _hurd_fd_write): Declare
        using __off64_t instead of __loff_t.
        * support/xunistd.h (xcopy_file_range): Declare using off64_t
        instead of loff_t.
	* sysdeps/unix/sysv/linux/generic/wordsize-32/overflow.h
	* sysdeps/unix/sysv/linux/lseek.c
	* sysdeps/unix/sysv/linux/lseek64.c
	* sysdeps/unix/sysv/linux/splice.c
        Throughout, use off64_t instead of loff_t.

	* sysdeps/unix/sysv/linux/sys/quota.h
        (dqoff): Use __off64_t instead of __loff_t.
        (quotactl): Declare using char * instead of caddr_t.
	* sysdeps/unix/sysv/linux/test-errno-linux.c
        (do_test): Cast to char * instead of caddr_t when calling quotactl.

	* elf/dl-map-segments.h (_dl_map_segments): Cast to void *
        instead of caddr_t when calling __mprotect and __mmap.
        * elf/dl-minimal.c (malloc): Declare page as char *, not caddr_t.
        * elf/dl-reloc.c (_dl_relocate_object): Declare textrels.start
        as char *, not caddr_t.  Cast to char *, not caddr_t, in
        pointer arithmetic.

	* intl/loadmsgcat.c: Remove two unnecessary casts to caddr_t
        when calling munmap. Change a third cast to target void *
        instead and add a comment explaining why this one is necessary.

	* locale/loadlocale.c (_nl_load_locale): Use NULL instead of
        `(caddr_t)0`, and remove an unnecessary cast to caddr_t when
        calling munmap.
        (_nl_unload_locale): Change casts when calling free and munmap
        to target char *, and add a comment explaining why they are
        necessary.

	* sysdeps/gnu/net/if.h
        (struct ifreq): Declare ifru_data as char *, not __caddr_t.
        (struct ifconf): Declare ifcu_buf as char *, not __caddr_t.

	* nis/nis_add.c
	* nis/nis_call.c
	* nis/nis_callback.c
	* nis/nis_checkpoint.c
	* nis/nis_findserv.c
	* nis/nis_intern.h
	* nis/nis_lookup.c
	* nis/nis_mkdir.c
	* nis/nis_modify.c
	* nis/nis_ping.c
	* nis/nis_remove.c
	* nis/nis_rmdir.c
	* nis/nis_server.c
	* nis/nis_table.c
	* nis/nis_util.c
	* nis/nss_nisplus/nisplus-grp.c
	* nis/nss_nisplus/nisplus-pwd.c
	* nis/rpcsvc/nis_callback.h
	* nis/rpcsvc/yp.h
	* nis/ypclnt.c
	* sunrpc/auth_des.c
	* sunrpc/auth_unix.c
	* sunrpc/authdes_prot.c
	* sunrpc/authuxprot.c
	* sunrpc/clnt_raw.c
	* sunrpc/clnt_tcp.c
	* sunrpc/clnt_udp.c
	* sunrpc/clnt_unix.c
	* sunrpc/key_call.c
	* sunrpc/pm_getmaps.c
	* sunrpc/pm_getport.c
	* sunrpc/pmap_clnt.c
	* sunrpc/pmap_prot2.c
	* sunrpc/pmap_rmt.c
	* sunrpc/proto.h
	* sunrpc/rpc/auth.h
	* sunrpc/rpc/clnt.h
	* sunrpc/rpc/pmap_clnt.h
	* sunrpc/rpc/pmap_rmt.h
	* sunrpc/rpc/rpc_msg.h
	* sunrpc/rpc/svc.h
	* sunrpc/rpc/xdr.h
	* sunrpc/rpc_clntout.c
	* sunrpc/rpc_cmsg.c
	* sunrpc/rpc_hout.c
	* sunrpc/rpc_prot.c
	* sunrpc/rpc_sample.c
	* sunrpc/rpc_svcout.c
	* sunrpc/svc.c
	* sunrpc/svc_authux.c
	* sunrpc/svc_raw.c
	* sunrpc/svc_tcp.c
	* sunrpc/svc_udp.c
	* sunrpc/svc_unix.c
	* sunrpc/xdr.c
	* sunrpc/xdr_array.c
	* sunrpc/xdr_mem.c
	* sunrpc/xdr_rec.c
	* sunrpc/xdr_ref.c
	* sunrpc/xdr_sizeof.c
	* sunrpc/xdr_stdio.c:
        Mechanically replace all uses of caddr_t with char *.

        * sunrpc/xdr_mem.c (xdrmem_create): Cast away const when
        setting xdrs->x_private and xdrs->x_base.
        * sunrpc/xdr_stdio.c (xdrstdio_getbytes): Correct argument
        types in definition to match prototype.