[llvm] [X86] Narrow BT/BTC/BTR/BTS compare + RMW patterns on very large integers (PR #165540)

[Augie Fackler via llvm-commits]

durin42 wrote:

I don't think we had those LLVM changes landed. I might spend some more time on this, probably Tuesday, but sadly there's a lot going on. :(

https://github.com/llvm/llvm-project/pull/165540