Fix some places where we were assuming that memory type had been legalized
to a simple type when lowering a truncating store of a vector type. In this
case for an EVT we'll return Expand as we should in all of the cases anyhow.

The testcase triggered at the one in VectorLegalizer::LegalizeOp, inspection
found the rest.

llvm-svn: 254061
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
index b465ffb..c581052 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
@@ -844,8 +844,7 @@
         SDValue Result = DAG.getNode(ISD::TokenFactor, dl, MVT::Other, Lo, Hi);
         ReplaceNode(SDValue(Node, 0), Result);
       } else {
-        switch (TLI.getTruncStoreAction(ST->getValue().getSimpleValueType(),
-                                        StVT.getSimpleVT())) {
+        switch (TLI.getTruncStoreAction(ST->getValue().getValueType(), StVT)) {
         default: llvm_unreachable("This action is not supported yet!");
         case TargetLowering::Legal: {
           EVT MemVT = ST->getMemoryVT();