[llvm] [InstCombine] Use known bits to simplify mask in foldSelectICmpAnd (PR #128741)

[Julian Nagele via llvm-commits]

juliannagele wrote:

Thanks! Here's a generalized version `assume`-ing that the rhs and bitmask are powers of 2 https://alive2.llvm.org/ce/z/RszbRS

https://github.com/llvm/llvm-project/pull/128741