[X86] Null out some redundant patterns for masked vector register to register...

[X86] Null out some redundant patterns for masked vector register to register moves. These can be accomplished with both aligned and unaligned opcodes.

Currently aligned is what is being used so remove the redundant patterns for the unaligned versions. But don't do this for the byte and word vector types since they don't have aligned versions.

llvm-svn: 261985