[clang] [compiler-rt] [llvm] [PGO][AMDGPU] Add uniformity-aware offload profile format and instrumentation (PR #190708)

[Yaxun Liu via cfe-commits]

yxsamliu wrote:

@lfmeadow Could you help review this PR when you get a chance? We have users depending on this work, and it has been rebased to ToT of main. Thanks.

https://github.com/llvm/llvm-project/pull/190708