[InstCombine] Generalize and-reduce pattern to handle `ne` case as well as `eq`

Following Sanjay's proposal from discussion in D118317, this patch
generalizes and-reduce handling to fold the following pattern
```
  icmp ne (bitcast(icmp ne (lhs, rhs)), 0)
```
into
```
  icmp ne (bitcast(lhs), bitcast(rhs))
```

https://alive2.llvm.org/ce/z/WDcuJ_

Differential Revision: https://reviews.llvm.org/D118431
Reviewed By: lebedev.ri