here:
1) We need to avoid processing sigma nodes as phi nodes for constraint generation.
2) We need to generate constraints for comparisons against constants properly.
This includes our first working ABCD test!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86498 91177308-0d34-0410-b5e6-96231b3b80d8
