[X86] Lower SEXTLOAD using SIGN_EXTEND_VECTOR_INREG. NCI.

The custom lowering in LowerExtendedLoad is doing the equivalent shuffle, so make use of existing lowering code to reduce duplication.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249243 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed