[clang] [llvm] [AMDGPU] Emit a waitcnt instruction after each memory instruction (PR #79236)

[Jun Wang via cfe-commits]

jwanggit86 wrote:

@jayfoad After trying the patch you provided above, it appears that this feature can indeed be done in SIInsertWaitcnt instead of SIMemoryLegalizer. Code has been updated accordingly. Pls take a look.

https://github.com/llvm/llvm-project/pull/79236