Handle resolvedAst for forwarding constructors and callType on unnamed mixin applications.

tests/compiler/dart2js/diagnostic_reporter_helper.dart

 // Copyright (c) 2015, 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 dart2js.diagnostic_reporter.helper;
 
 import 'package:compiler/src/diagnostics/diagnostic_listener.dart';
 import 'package:compiler/src/diagnostics/messages.dart';
 import 'package:compiler/src/diagnostics/spannable.dart';
 import 'package:compiler/src/diagnostics/source_span.dart';
@@ skipping 55 matching lines @@
 
   @override
   SourceSpan spanFromSpannable(Spannable node) {
     return reporter.spanFromSpannable(node);
   }
 
   @override
   withCurrentElement(Element element, f()) {
     return reporter.withCurrentElement(element, f);
   }
+
+  @override
+  bool get hasReportedError => reporter.hasReportedError;
 }