[llvm] [AMDGPU] Remove unnecessary predicates from aliases. NFC. (PR #91602)

[Jay Foad via llvm-commits]

jayfoad wrote:

> > Or if you are close to merging #89288 then I'll wait for you to merge that one first.
> 
> I just merged it.

Thanks. I rebased this patch which fixes the "predicates in Requires will apply to the whole instruction" problem.

https://github.com/llvm/llvm-project/pull/91602