Older versions such as binutils 2.35.2 do not recognize
PT_GNU_PROPERTY.

Fixes commit d3f2b71ef1d146137a25dd1367d97a14fac341c6
("aarch64: Fix tests not compatible with targets supporting GCS").

 - Add GCS marking to some of the tests when target supports GCS
 - Fix tst-ro-dynamic-mod.map linker script to avoid removing
   GNU properties
 - Add header with macros for GNU properties

Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Wilco Dijkstra <Wilco.Dijkstra@arm.com>

Use the same code to compute the TLS block size and its alignment.
The code in elf/dl-tls.c is linked in anyway for all binaries
due to the reference to _dl_tls_static_surplus_init.

It is not possible to call _dl_allocate_tls_storage directly
because malloc is not available in the static case.  (The
dynamic linker uses the minimal malloc at this stage.)  Therefore,
split _dl_tls_block_size_with_pre and _dl_tls_block_align from
_dl_allocate_tls_storage, and call those new functions from
__libc_setup_tls.

This fixes extra TLS allocation for the static case, and apparently
some pre-existing bugs as well (the independent recomputation of
TLS block sizes in init_static_tls looks rather suspect).

Fixes commit 0e411c5d3098982d67cd2d7a233eaa6c977a1869 ("Add generic
'extra TLS'").

The old code used the slotinfo array as a scratch area to pass the
list of TLS-using objects to _dl_determine_tlsoffset.  All array
entries are subsequently overwritten by _dl_add_to_slotinfo,
except the first one.  The link maps are usually not at their
right position for their module ID in the slotinfo array, so
the initial use of the slotinfo array would be incorrect if not
for scratch purposes only.

In _dl_tls_initial_modid_limit_setup, the old code relied that
some link map was written to the first slotinfo entry.  After the
change, this no longer happens because TLS module ID zero is unused.
It's also necessary to move the call after the real initialization
of the slotinfo array.

The __ifunc_resolver macro expands to:

  extern __typeof (__redirect_name) name __attribute__ ((ifunc ("iname_ifunc")));
  static __typeof (__redirect_name) *name_ifunc (void) { [...] };

And although NAME_IFUNC is and alias for NAME, clang-18 still emits
an 'unused function 'name_ifunc' [-Werror,-Wunused-function]'
warning.

rather than pthread_self (), which in htl is not a pointer into dtv, but an
index.

Add the logic to append an 'extra TLS' block in the TLS block allocator
with a generic stub implementation. The duplicated code in
'csu/libc-tls.c' and 'elf/dl-tls.c' is to handle both statically linked
applications and the ELF dynamic loader.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>

This will be needed to compute __rseq_offset outside of the TLS
relocation machinery.

Reviewed-by: Michael Jeanson <mjeanson@efficios.com>