[SelectionDAG][X86] Don't use ->getValueType(0) after a call to getOperand to...

[SelectionDAG][X86] Don't use ->getValueType(0) after a call to getOperand to get the type of the operand.

getOperand returns an SDValue that contains the node and the result number. There is no guarantee that the result number if 0. By using the -> operator we are calling SDNode::getValueType rather than SDValue::getValueType. This requires supplying a result number and we shouldn't assume it was 0.

I don't have a test case. Just noticed while cleaning up some other code and saw that it occurred in other places.

llvm-svn: 321397