[llvm] [X86] Use GFNI for LZCNT vXi8 ops (PR #141888)

[via llvm-commits]

houngkoungting wrote:

HI  @RKSimon  ,  Thanks for the feedback. Some issues (include whitespace...) are still not fully addressed — I will work on them and submit an updated it tomorrow.

https://github.com/llvm/llvm-project/pull/141888