[llvm] [AMDGPU] Enable copy from VCC to SHARED_BASE. (PR #164138)

[Jay Foad via llvm-commits]

jayfoad wrote:

> can you please point me to where the verification should happen? I looked in MachineVerifier but the input is the COPY instruction, so no verification of the S_MOV_B64.

You would have to run the verifier after you have converted the COPY to S_MOV_B64, so after the ExpandPostRAPseudos (aka postrapseudos) pass. You could run `llc -verifymachineinstrs` to verify after every pass.

https://github.com/llvm/llvm-project/pull/164138