[InstCombine] Add tests for (A > 0) | (A < 0) -> zext (A != 0) fold (NFC)

Tests for an upcoming  (A > 0) | (A < 0) -> zext (A != 0) fold.
Related issue:
[[ https://github.com/llvm/llvm-project/issues/62586 | (a > b) | (a < b) is not simplified only for the case b=0 ]]

Differential Revision: https://reviews.llvm.org/D154089