[clang] [llvm] [clang-tools-extra] [AMDGPU] Fix GCNRewritePartialRegUses pass: vector regclass is selected instead of scalar. (PR #69957)

[Valery Pykhtin via cfe-commits]

vpykhtin wrote:

> I think the code change looks fine. I left a few questions inline about existing code -- you don't necessarily need to address these.
> 
> Could you regenerate the tests as a separate NFC commit (or PR), so this PR only shows test changes from the code change?

Thank you for the review, Carl!

I can regenerate the tests but I'm not sure how to do it best here: submit the updated tests, rebase this PR's branch on top of the commit and then force push the branch? Or I can simply merge _main_ with the updated tests commit into this PR's branch?

https://github.com/llvm/llvm-project/pull/69957