[llvm] [AMDGPU][AMDGPUDemoteSCCBranchToExecz] demote s_cbranch_scc0/1 branches into vcmp + s_cbranch_execz branches (PR #110284)

[Juan Manuel Martinez Caamaño via llvm-commits]

jmmartinez wrote:

I've updated the commit with an explanation on the first comment.

https://github.com/llvm/llvm-project/pull/110284