[llvm] [AMDGPU][GFX1250] Insert S_WAIT_XCNT for SMEM and VMEM load-stores (PR #145566)

[Christudasan Devadasan via llvm-commits]

cdevadas wrote:

### Merge activity

* **Jun 25, 5:08 AM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/145566).


https://github.com/llvm/llvm-project/pull/145566