[AArch64][GlobalISel] Walk through G_AND in TB(N)Z bit calculation

Given

```
tb(n)z (and x, m), b
```

Where the `b`-th bit of `m` is 1,

```
tb(n)z (and x, m), b == tb(n)z x, b
```

So, we can walk past a `G_AND` in this case.

Also add test/CodeGen/AArch64/GlobalISel/opt-fold-and-tbz-tbnz.mir to test this.

Differential Revision: https://reviews.llvm.org/D73790