Verifier: Make sure masked load/store alignment is a power of 2

The same should also be done for scatter/gather, but the verifier
doesn't check those at all now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356094 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed