[GlobalISel] Combine (logic_op (op x...), (op y...)) -> (op (logic_op x, y))

This implements

```
(logic_op (op x...), (op y...)) -> (op (logic_op x, y))
```

when `op` is an extend, a shift, or an and.

This is similar to `DAGCombiner::hoistLogicOpWithSameOpcodeHands`
(with a bunch of missing cases, e.g. G_TRUNC, G_BITCAST, etc.)

This is implemented so it works both pre and post-legalization.

This also adds a general way to add a series of instructions in a combine.
(`applyBuildInstructionSteps`).

Differential Revision: https://reviews.llvm.org/D85050