[llvm] X86: Add pattern for optimized BLSIC IR form (PR #209814)

[via llvm-commits]

Logans-olo wrote:

> So I run build/bin/llvm-lit --update-tests llvm/test/CodeGen/X86/tbm_patterns.ll, and then move into build directory, and run ninja check-llvm-codegen. I am passing all that are supported. Is that sufficient?

And I should be running this command and ninja after every change to a testing file correct? I think that was part of my problem as well.

https://github.com/llvm/llvm-project/pull/209814