[llvm] [InstCombine] Fold `scmp(x -nsw y, 0)` to `scmp(x, y)` (PR #105583)

[Nikita Popov via llvm-commits]

nikic wrote:

Huh, that's interesting. Didn't expect that ucmp has constants mostly on the left.

https://github.com/llvm/llvm-project/pull/105583