[InstCombine] Add regression test cases for bitreverse optimization; NFC

Fold the following case on IR InstCombine pass. This patch includes the new test cases for this optimization

```
bitreverse(logic_op(x, bitreverse(y))) -> logic_op(bitreverse(x), y)
bitreverse(logic_op(bitreverse(x), y)) -> logic_op(x, bitreverse(y))
bitreverse(logic_op(bitreverse(x), bitreverse(y))) -> logic_op(x, y) with multi-use
```

Reviewed By: goldstein.w.n

Differential Revision: https://reviews.llvm.org/D151245