Implement a "union-findy" version of DS-Analysis, which eliminates the
Referrers list on DSNodes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5536 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DataStructure/Steensgaard.cpp b/lib/Analysis/DataStructure/Steensgaard.cpp
index 0458670..bd6a7e9 100644
--- a/lib/Analysis/DataStructure/Steensgaard.cpp
+++ b/lib/Analysis/DataStructure/Steensgaard.cpp
@@ -193,6 +193,8 @@
       ++i;                            // Skip this call site...
   }
 
+  RetValMap.clear();
+
   // Update the "incomplete" markers on the nodes, ignoring unknownness due to
   // incoming arguments...
   ResultGraph->maskIncompleteMarkers();