[ConstantFolding] Fold masked loads

We can constant fold a masked load if the operands are appropriately
constant.

Differential Revision: http://reviews.llvm.org/D22324

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275352 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed