Fix another variant of PR 7191.  Also add a testcase
Mon Ping provided; unfortunately bugpoint failed to
reduce it, but I think it's important to have a test for
this in the suite.  8023512.

llvm-svn: 104624
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index df1a0a3..6bddd78 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3832,8 +3832,12 @@
   if (N0.getOpcode() == ISD::TRUNCATE) {
     SDValue NarrowLoad = ReduceLoadWidth(N0.getNode());
     if (NarrowLoad.getNode()) {
-      if (NarrowLoad.getNode() != N0.getNode())
+      SDNode* oye = N0.getNode()->getOperand(0).getNode();
+      if (NarrowLoad.getNode() != N0.getNode()) {
         CombineTo(N0.getNode(), NarrowLoad);
+        // CombineTo deleted the truncate, if needed, but not what's under it.
+        AddToWorkList(oye);
+      }
       return DAG.getNode(ISD::ANY_EXTEND, N->getDebugLoc(), VT, NarrowLoad);
     }
   }