[llvm] [NVPTX] cleanup & canonicalize `mov` (PR #129344)

[Thomas Raoux via llvm-commits]

ThomasRaoux wrote:

> Any chance you can post a minimized reproducer on godbolt?

I don't have a minimized reproducer yet. As it is related to ptxas optimization making it minimal is a challenge

https://github.com/llvm/llvm-project/pull/129344