Cleanup argument mismatch message.

sdk/lib/_internal/compiler/implementation/elements/elements.dart

 // Copyright (c) 2012, 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 elements;
 
 
 import '../tree/tree.dart';
 import '../util/util.dart';
 import '../resolution/resolution.dart';
@@ skipping 509 matching lines @@
   // TODO(johnniwinther): Remove this method.
   static String reconstructConstructorName(Element element) {
     String className = element.enclosingClass.name;
     if (element.name == '') {
       return className;
     } else {
       return '$className\$${element.name}';
     }
   }
 
+  static String constructorNameForDiagnostics(String className,
+                                              String constructorName) {
+    String classNameString = className;
+    String constructorNameString = constructorName;
+    return (constructorName == '')
+        ? classNameString
+        : "$classNameString.$constructorNameString";
+  }
+
   /// Returns `true` if [name] is the name of an operator method.
   static bool isOperatorName(String name) {
     return name == 'unary-' || isUserDefinableOperator(name);
   }
 
   /**
    * Map an operator-name to a valid JavaScript identifier.
    *
    * For non-operator names, this method just returns its input.
    *
@@ skipping 785 matching lines @@
   bool get isDeclaredByField;
 
   /// Returns `true` if this member is abstract.
   bool get isAbstract;
 
   /// If abstract, [implementation] points to the overridden concrete member,
   /// if any. Otherwise [implementation] points to the member itself.
   Member get implementation;
 }