[llvm] [AMDGPU] Allocate i1 argument to SGPRs (PR #72461)

[Jun Wang via llvm-commits]

jwanggit86 wrote:

@arsenm In one of your comments, you mentioned promoting "inreg i1" before it's being allocated. This is done in the latest commit. Note that, on a wavefront64 GPU, an "inreg i1" argument would be allcoated to a 32b sgpr while an ordinary i1 arg would be allocated to a 64b sgpr. Is this what you had in mind?

Also I'm waiting for your further comments on SILowerI1Copies.

https://github.com/llvm/llvm-project/pull/72461