[InstCombine] Extend `foldICmpBinOp` to `add`-like `or`. (#71396)

InstCombine canonicalizes `add` to `or` when possible, but this makes
some optimizations applicable to `add` to be missed because they don't
realize that the `or` is equivalent to `add`.

In this patch we generalize `foldICmpBinOp` to handle such cases.