[InstCombine][InstSimplify] Add baseline tests for icmp bool with not on LHS; NFC

See D114666 for proposed code change to instsimplify.

The difference between the CHECK result of these 2 tests
highlights missed folds in instsimplify
(e.g. (icmp eq (xor X, true), false) -> X) that are
already being handled by instcombine.

The tests are based on:
llvm/test/Transforms/InstSimplify/icmp-bool-constant.ll

Differential Revision: https://reviews.llvm.org/D115209