[llvm] [InstCombine] Propagate poison pow[i], [us]add, [us]sub and [us]mul (PR #146750)

[Luke Lau via llvm-commits]

https://github.com/lukel97 approved this pull request.

LGTM, I think there's a few fold to poison cases in `simplifyBinaryIntrinsic` can probably be removed afterwards as an NFC

https://github.com/llvm/llvm-project/pull/146750