Added required passes for CUDNN backend

llvm/lib/Transforms/DFG2LLVM_CUDNN/DFG2LLVM_CUDNN.cpp

@@ -45,6 +45,14 @@ struct DFG2LLVM_CUDNN : public DFG2LLVM {
 private:
 
 public:
+
+  void getAnalysisUsage(AnalysisUsage &AU) const {
+    AU.addRequired<BuildDFG>();
+    AU.addRequired<InPlaceDFGAnalysisWrapper>();
+    AU.addPreserved<BuildDFG>();
+    AU.addPreserved<InPlaceDFGAnalysisWrapper>();
+  }
+
   bool runOnModule(Module &M);
 };