Instantiate DefaultDOTGraphTraits

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90133 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/ScheduleDAGPrinter.cpp b/lib/CodeGen/ScheduleDAGPrinter.cpp
index 4851d49..5855f96 100644
--- a/lib/CodeGen/ScheduleDAGPrinter.cpp
+++ b/lib/CodeGen/ScheduleDAGPrinter.cpp
@@ -32,6 +32,9 @@
 namespace llvm {
   template<>
   struct DOTGraphTraits<ScheduleDAG*> : public DefaultDOTGraphTraits {
+
+  DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
+
     static std::string getGraphName(const ScheduleDAG *G) {
       return G->MF.getFunction()->getName();
     }