Summary:
This was a lot of code that was only used for upstream LLVM builds of
AMDGPU offloading. We have a generic and fast `malloc` in `libc` now so
just use that. Simplifies code, can be added back if we start providing
alternate forms but I don't think there's a single use-case that would
justify it yet.

On AIX, it generates libomp for both static and dynamic. There is no
need to create symbolic links to libomp.so.

---------

Co-authored-by: Xing Xue <xingxue@outlook.com>

When OMPT is enabled, the stack pointer was not saved to frame pointer
register immediately after storing the frame pointer to the stack.
Therefore the frame pointers did not constitute a proper chain.
Fixes [#163352](https://github.com/llvm/llvm-project/issues/163352)

LLVM's cmake standard explicitly lists all source in the CMakeLists.txt.
Remove globbing for source files in OpenMP's CMakeLists.txt.

Also see #4899, #71404, https://reviews.llvm.org/D79906,
https://reviews.llvm.org/D31363, https://reviews.llvm.org/D61275,
https://discourse.llvm.org/t/cmake-builds-clang/11536, and CMake's note
at https://cmake.org/cmake/help/latest/command/file.html#glob. Two
reasons to not glob for source files is that it breaks bisecting and
incremental builds. Renaming a file, reverting or checking out an older
reversion where a newly added source file disappears again will not
trigger a CMake configure step and make the build fail because of a
non-existing source file.

Implementation files using the Intel syntax explicitly specify it.
Do the same for the few files using AT&T syntax.

This also enables building LLVM with `-mllvm -x86-asm-syntax=intel` in one's Clang config files
(i.e. a global preference for Intel syntax).

No functional change intended.

Add equality op which checks 'Kind'
 - For now this seems more reasonable than defaulting to true

Chose to keep toString and equality unit tests separate

Fix https://github.com/llvm/llvm-project/issues/156679

There is a mismatch between the preprocessor guards around the include
of `hwloc.h` and those protecting its usages, leading to build failures
on Darwin: https://github.com/spack/spack-packages/pull/1212

This change introduces `KMP_HWLOC_ENABLED` that reflects
whether hwloc is actually used.

Corrects the spelling of 'IsGlobaLinkage' to 'IsGlobalLinkage' in
XCOFF-related code, comments, and tests across the codebase.