[llvm] [AMDGPU] Swap select operands to allow later v_cndmask shrinking into vop2 (PR #142354)

[Nicolai Hähnle via llvm-commits]

https://github.com/nhaehnle commented:

The logic makes sense to me and this looks like generally a nice improvement. I do have one inline question though.

https://github.com/llvm/llvm-project/pull/142354