X86: When expanding PCMPGTQ to PCMPGTD we always want to compare the lower halves as unsigned.

Take #2 on fixing PR15977.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182486 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed