Added InstCombine transform for pattern "(A & B) ^ (A ^ B) -> (A | B)"

Patch idea by Ankit Jain !

Differential Revision: http://reviews.llvm.org/D4618



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213677 91177308-0d34-0410-b5e6-96231b3b80d8