[llvm] [AMDGPU][True16][CodeGen] update wwm reg sorting check condition (PR #135053)

[Brox Chen via llvm-commits]

broxigarchen wrote:

> Please add a test

I checked the wwm reg related test and it seems I could not find any thing that test for the sorting of the reserved reg. Hi @cdevadas are you comfortable with merging this as it, or is there a recommended test that I can look into? Thanks for the hint!

https://github.com/llvm/llvm-project/pull/135053