[llvm] [AMDGPU][SIMemoryLegalizer][GFX12] Correctly insert sample/bvhcnt (PR #161637)

[Sameer Sahasrabuddhe via llvm-commits]

ssahasra wrote:

What would be a good place to define "correctly insert samplecnt/bvhcnt"? I believe the patch inserts these waitcnts for all releases and seq_cst operations, but not for acquire operations. Is that the intention? Is this documented somewhere?

https://github.com/llvm/llvm-project/pull/161637