[X86] Fix DecodeVPERMVMask to handle cases where the constant pool entry has a different type than the shuffle itself.

This is especially important for 32-bit targets with 64-bit shuffle elements.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284453 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed