[InstCombine][NFC] Add test to show missing fold for icmp ult/uge (shl %x, C2), C1.

Summary:
'shl' inequality test

```
  icmp ult/uge (shl %x, C2), C1 iff C1 is power of two
```

can be simplified as 'and' equality test

```
  icmp eq/ne (and %x, (lshr -C1, C2)), 0.
```

Reviewers: lebedev.ri, efriedma

Reviewed By: lebedev.ri

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63670

llvm-svn: 364256