Handle unresolved elements in the new IR

sdk/lib/_internal/compiler/implementation/dart_backend/dart_codegen.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart_codegen;
 
 import 'dart_tree.dart' as tree;
 import 'dart_printer.dart';
 import 'dart_tree_printer.dart' show TreePrinter;
 import '../tree/tree.dart' as frontend;
@@ skipping 536 matching lines @@
     } else if (type is VoidType) {
       return new TypeAnnotation('void')
           ..dartType = type;
     } else if (type is TypeVariableType) {
       return new TypeAnnotation(type.name)
           ..dartType = type;
     } else if (type is DynamicType) {
       return new TypeAnnotation("dynamic")
           ..dartType = type;
     } else if (type is MalformedType) {
-      // treat malformed types as dynamic
-      return new TypeAnnotation("dynamic")
-          ..dartType = const DynamicType();
+      return new TypeAnnotation(type.name)
+          ..dartType = type;
     } else {
       throw "Unsupported type annotation: $type";
     }
   }
 
   /// Like [emitType] except the dynamic type is converted to null.
   TypeAnnotation emitOptionalType(DartType type) {
     if (type.treatAsDynamic) {
       return null;
     } else {
@@ skipping 70 matching lines @@
     return new Identifier(name)
                ..element = exp.element;
   }
 
   Expression visitFunction(FunctionConstExp exp) {
     return new Identifier(exp.element.name)
                ..element = exp.element;
   }
 
 }