[X86] Add support to assembler and MCInst lowering to use the other vmovq %xmmX, %xmmX encoding if it would be a shorter VEX encoding.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250014 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed