[llvm] [MachineLICM] Correctly Apply Register Masks (PR #95746)

[Pierre van Houtryve via llvm-commits]

Pierre-vh wrote:

I think I have a fix, the issue is with how we apply the regmask indeed so this patch is at fault.
The current logic isn't quite right and the lack of test coverage didn't help. I'll need some time to create a testcase from the reproducer.

https://github.com/llvm/llvm-project/pull/95746