Version 2 was added more than two years ago
(https://github.com/llvm/llvm-project/commit/6015a045d768feab3bae9ad9c0c81e118df8b04a).
So it should be safe to deprecate older versions.

This is just a stub for now.

This patch transforms:

  X && *X == Y

to:

  X == Y

where X is of std::optional<T>, and Y is of T or similar.

This implements arm, armeb, thumb, thumbeb PLT entries parsing support
in ELF for llvm-objdump.

Implementation is similar to AArch64MCInstrAnalysis::findPltEntries. PLT
entry signatures are based on LLD code for PLT generation
(ARM::writePlt).

llvm-objdump tests are produced from lld/test/ELF/arm-plt-reloc.s,
lld/test/ELF/armv8-thumb-plt-reloc.s.

It allows access to subtarget features, collected in llvm-objdump.cpp,
from findPltEntries, which will be used in
https://github.com/llvm/llvm-project/pull/130764.

The module currently stores the target triple as a string. This means
that any code that wants to actually use the triple first has to
instantiate a Triple, which is somewhat expensive. The change in #121652
caused a moderate compile-time regression due to this. While it would be
easy enough to work around, I think that architecturally, it makes more
sense to store the parsed Triple in the module, so that it can always be
directly queried.

For this change, I've opted not to add any magic conversions between
std::string and Triple for backwards-compatibilty purses, and instead
write out needed Triple()s or str()s explicitly. This is because I think
a decent number of them should be changed to work on Triple as well, to
avoid unnecessary conversions back and forth.

The only interesting part in this patch is that the default triple is
Triple("") instead of Triple() to preserve existing behavior. The former
defaults to using the ELF object format instead of unknown object
format. We should fix that as well.

gfx940 and gfx941 are no longer supported. This is one of a series of
PRs to remove them from the code base.

This PR removes all non-documentation occurrences of gfx940/gfx941 from
the llvm directory, and the remaining occurrences in clang.

Documentation changes will follow.

For SWDEV-512631

Describes PLT entries for hexagon.

This patch introduces support for the Hexagon V75 architecture. It
includes instruction formats, definitions, encodings, scheduling
classes, and builtins/intrinsics.

Identified with misc-include-cleaner.