[llvm] [InstCombine] Fold `(icmp pred (trunc nuw/nsw X), C)` -> `(icmp pred X, (zext/sext C))` (PR #87935)

[via llvm-commits]

goldsteinn wrote:

Think long term, we can probably generalize just about any fold we where previously doing with `sext` to work for `trunc nsw`, `zext` to work with `trunc nuw`, and `zext nneg` to work with `trunc nuw nsw`.

https://github.com/llvm/llvm-project/pull/87935