[InstSimplify] use ConstantRange to simplify more and-of-icmps

We can simplify (and (icmp X, C1), (icmp X, C2)) to one of the icmps in many cases. 
I had to check some of these with Alive to prove to myself it's right, but everything 
seems to check out. Eg, the code in instcombine was completely ignoring predicates with 
mismatched signedness.

Handling or-of-icmps would be a follow-up step.

Differential Revision: https://reviews.llvm.org/D32143

llvm-svn: 301260