[X86] Remove a branch on SSE4.1 from LowerLoad

We should be able to use getExtendInVec with or without sse4.1 to produce a SIGN_EXTEND_VECTOR_INREG.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@347095 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed