Replace EVT with MVT in many of the shuffle lowering functions. Keeps compiler from generating unneeded checks and handling for extended types.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188361 91177308-0d34-0410-b5e6-96231b3b80d8
Replace EVT with MVT in isVectorShift. Keeps compiler from generating unneeded checks and handling for extended types.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188362 91177308-0d34-0410-b5e6-96231b3b80d8