[ConstantRange] Make getEquivalentICmp smarter

This change teaches getEquivalentICmp to be smarter about generating
ICMP_NE and ICMP_EQ predicates.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283057 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed