[X86] Teach combineX86ShuffleChain that AllowIntDomain requires at least SSE2.

I don't have a good test case for this at the moment. I was playing around with a change in legalizing and triggered this code to produce a PSHUFD with sse1 only.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319066 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed