[llvm] AMDGPU: Add more baseline tests for VGPR MFMA rewrite pass (PR #148173)

[Matt Arsenault via llvm-commits]

arsenm wrote:

### Merge activity

* **Jul 14, 10:08 AM UTC**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/148173).


https://github.com/llvm/llvm-project/pull/148173