Add another copy ctor form


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@4251 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DataStructure/DataStructure.cpp b/lib/Analysis/DataStructure/DataStructure.cpp
index cc0b8d8..4b3be84 100644
--- a/lib/Analysis/DataStructure/DataStructure.cpp
+++ b/lib/Analysis/DataStructure/DataStructure.cpp
@@ -371,6 +371,11 @@
   RetNode = cloneInto(G, ValueMap, NodeMap);
 }
 
+DSGraph::DSGraph(const DSGraph &G, std::map<const DSNode*, DSNode*> &NodeMap)
+  : Func(G.Func) {
+  RetNode = cloneInto(G, ValueMap, NodeMap);
+}
+
 DSGraph::~DSGraph() {
   FunctionCalls.clear();
   ValueMap.clear();