[InstCombine] Support folding and/or/xor with a constant vector RHS into selects and phis

Currently we only fold with ConstantInt RHS. This generalizes to any Constant RHS.

Differential Revision: https://reviews.llvm.org/D31610



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299466 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed