[llvm] [InstCombine] Add transforms `(icmp spred (and X, Y), X)` if `X` or `Y` are known signed/unsigned (PR #94417)

[Nikita Popov via llvm-commits]

https://github.com/nikic requested changes to this pull request.

Is isKnownNonNegative() instead of getKnownSign(). Only use getKnownSign() if you need to handle both the negative and the non-negative case.

The special case that getKnownSign() implements is intended for llvm.abs only, and should not be taken as justification to use this API in any other circumstance.

https://github.com/llvm/llvm-project/pull/94417