[clang] [Clang][HIP] Deprecate the AMDGCN_WAVEFRONT_SIZE macros (PR #112849)

[Shilei Tian via cfe-commits]

https://github.com/shiltian commented:

Just a heads up, this change is gonna break some OpenMP tests, specifically those prefix with `ompx`.

https://github.com/llvm/llvm-project/pull/112849