Commit the correct BuildDFG with multiple launch support

llvm/include/llvm/BuildDFG/BuildDFG.h

@@ -30,6 +30,7 @@ struct BuildDFG : public ModulePass {
 private:
   // Member variables
   DFInternalNode *Root;
+  std::vector<DFInternalNode*> Roots;
 
   HandleToDFNode HandleToDFNodeMap;   // This map associates the i8* pointer
   // with the DFNode structure that it
@@ -60,6 +61,7 @@ public:
 
   //TODO: Maybe make these fields const
   DFInternalNode *getRoot() const;
+  std::vector<DFInternalNode*> &getRoots();
   HandleToDFNode &getHandleToDFNodeMap();
   HandleToDFEdge &getHandleToDFEdgeMap();