Revert 121907 (it causes llc crash) and apply original patch from PR9817.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131926 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 4f56ab6..d219c58 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -994,6 +994,9 @@
           dbgs() << "\nWith: ";
           RV.getNode()->dump(&DAG);
           dbgs() << '\n');
+    
+    // Transfer debug value.
+    DAG.TransferDbgValues(SDValue(N, 0), RV);
     WorkListRemover DeadNodes(*this);
     if (N->getNumValues() == RV.getNode()->getNumValues())
       DAG.ReplaceAllUsesWith(N, RV.getNode(), &DeadNodes);