[llvm] [X86] Keep bitcasted mask zero-tests in k-registers (PR #207908)

[Jaeuk Lee via llvm-commits]

skku970412 wrote:

I confirm that I have read the LLVM contribution policies, including the LLVM AI Tool Use Policy. AI tool usage is noted in the PR description.

https://github.com/llvm/llvm-project/pull/207908