Revert "[GlobalISel] Fold xor(cmp(pred, _, _), 1) -> cmp(inverse(pred), _, _)"...

Revert "[GlobalISel] Fold xor(cmp(pred, _, _), 1) -> cmp(inverse(pred), _, _)" (and dependent patch "Optimize away a Not feeding a brcond by using tbz instead of tbnz.")

This reverts commit 8ad8f484. It causes crashes when running `ninja check-llvm-codegen-aarch64-globalisel`, e.g.
http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/24132/steps/test-stage1-compiler/logs/stdio.
Note that the crash does not seem to reproduce in debug builds.

5ded4442 depends on this, so revert that too.