[llvm] [InstCombine] Remove INT_MIN poison check from abs(X) u< C --> X + (C-1) u<= 2*(C-1) fold. (PR #219264)

[Nikita Popov via llvm-commits]

nikic wrote:

Please add an [alive2 proof](https://llvm.org/docs/InstCombineContributorGuide.html#proofs) to the PR description.

https://github.com/llvm/llvm-project/pull/219264