This change adds boilerplate code to implement the object::ObjectFile
interface for the DXContainer object file and an empty implementation of
the objdump Dumper object.

Adding an ObjectFile implementation for DXContainer is a bit odd because
the DXContainer format doesn't have a symbol table, so there isn't a
reasonable implementation for the SymbolicFile interfaces. That said, it
does have sections, and it will be useful for objdump to be able to
inspect some of the structured data stored in some of the special named
sections.

At this point in the implementation it can't do much other than dump the
part names, offsets, and sizes. Dumping detailed structured section
contents to be extended in subsequent PRs.

Fixes #151433

A previous commit (82f75ed) made clang ignore .gch files that were not
Clang AST files. This broke `-gmodules`, which embeds the Clang AST into
an object file containing debug info.

This changes the probing to detect any file format recognized by
`llvm::identify_magic()` as potentially containing a Clang AST.

Previous PR: https://github.com/llvm/llvm-project/pull/69204

Summary:
More SPIR-V related patches are being upstreamed. We should add support
to detect when a binary file is SPIR-V. This will be used in the future
when support for SPIR-V is added to the offloading runtime or more
support for bundling.

The magic number is described in the official documentation:
https://registry.khronos.org/SPIR-V/specs/1.0/SPIRV.html#Magic. Notably,
SPIR-V files are streams of 32-bit words. This means that the magic
numbers differ depending on the endianness. Here we simply check the
strandard and byte-reversed versions.

Original PR: https://github.com/llvm/llvm-project/pull/67162

The commit was reverted due to UB detected by santizer:

https://lab.llvm.org/buildbot/#/builders/238/builds/5955

clang/lib/Driver/OffloadBundler.cpp:1012:25: runtime error:
 load of misaligned address 0xaaaae2d90e7c for type
 'const uint64_t' (aka 'const unsigned long'), which
 requires 8 byte alignment

It was fixed by using memcpy instead of dereferencing int*
casted from unaligned char*.

This reverts commit a1e81d2ead02e041471ec2299d7382f80c4dbba6.

Revert "Fix test hip-offload-compress-zlib.hip"

This reverts commit ba01ce60665848478ba4e76190907153a8c26fe9.

Revert due to sanity fail at

https://lab.llvm.org/buildbot/#/builders/5/builds/37188

https://lab.llvm.org/buildbot/#/builders/238/builds/5955

/b/sanitizer-aarch64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Driver/OffloadBundler.cpp:1012:25: runtime error: load of misaligned address 0xaaaae2d90e7c for type 'const uint64_t' (aka 'const unsigned long'), which requires 8 byte alignment
0xaaaae2d90e7c: note: pointer points here
  bc 00 00 00 94 dc 29 9a  89 fb ca 2b 78 9c 8b 8f  77 f6 71 f4 73 8f f7 77  73 f3 f1 77 74 89 77 0a
              ^
    #0 0xaaaaba125f70 in clang::CompressedOffloadBundle::decompress(llvm::MemoryBuffer const&, bool) /b/sanitizer-aarch64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Driver/OffloadBundler.cpp:1012:25
    #1 0xaaaaba126150 in clang::OffloadBundler::ListBundleIDsInFile(llvm::StringRef, clang::OffloadBundlerConfig const&) /b/sanitizer-aarch64-linux-bootstrap-ubsan/build/llvm-project/clang/lib/Driver/OffloadBundler.cpp:1089:7

Will reland after fixing it.

Add option -f[no-]offload-compress to clang to enable/disable
compression of device binary for HIP. By default it is disabled.

Add option -compress to clang-offload-bundler to enable compression of
offload bundle. By default it is disabled.

When enabled, zstd or zlib is used for compression when available.

When disabled, it is NFC compared to previous behavior. The same offload
bundle format is used as before.

Clang-offload-bundler automatically detects whether the input file to be
unbundled is compressed and the compression method and decompress if
necessary.

https://reviews.llvm.org/D131909

We use the `OffloadBinary` to create binary images of offloading files
and their corresonding metadata. This patch changes this to inherit from
the base `Binary` class. This allows us to create and insepect these
more generically. This patch includes all the necessary glue to
implement this as a new binary format, along with added the magic bytes
we use to distinguish the offloading binary to the `file_magic`
implementation.

Reviewed By: tra

Differential Revision: https://reviews.llvm.org/D126812

This silences warnings encountered on some bots.

Nvidia uses fatbinaries to bundle all of their device code. This patch
adds the magic number "0x50ed55ba" used in their propeitary format to
the list of magic identifies. This is technically undocumented and could
unlikely be changed by Nvidia in the future.

Reviewed By: tra

Differential Revision: https://reviews.llvm.org/D120932