[llvm] [InstCombine] fold sub (and (add x, pow2), ~pow2), x -> and x, pow2 (PR #230796)

[Nikita Popov via llvm-commits]

nikic wrote:

> Proof: https://alive2.llvm.org/ce/z/DXHtNs

The power of two check compares C1 instead of ctpop, so it only shows the C1 == 1 case :) Still verified with that fixed though...

https://github.com/llvm/llvm-project/pull/230796