Remove an unused version of getMemIntrinsicNode and getNode. Additionally, these were calling makeVTList with the pointers passed in which would were unlikely to belong to SelectionDAG and likely would have just been stack pointers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207326 91177308-0d34-0410-b5e6-96231b3b80d8
Convert SelectionDAG::getNode methods to use ArrayRef<SDValue>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207327 91177308-0d34-0410-b5e6-96231b3b80d8