Compute mixin application constructors in the ClassElement.constructors getter.

pkg/analyzer/test/generated/element_test.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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine.element_test;
 
 import 'package:analyzer/src/generated/ast.dart';
@@ skipping 2362 matching lines @@
     typeElement.constructors = <ConstructorElement>[
       constructorOne,
       constructorTwo
     ];
     InterfaceTypeImpl type = new InterfaceTypeImpl(typeElement);
     expect(type.constructors, hasLength(2));
   }
 
   void test_getConstructors_empty() {
     ClassElementImpl typeElement = ElementFactory.classElement2("A");
+    typeElement.constructors = ConstructorElement.EMPTY_LIST;
     InterfaceTypeImpl type = new InterfaceTypeImpl(typeElement);
     expect(type.constructors, isEmpty);
   }
 
   void test_getElement() {
     ClassElementImpl typeElement = ElementFactory.classElement2("A");
     InterfaceTypeImpl type = new InterfaceTypeImpl(typeElement);
     expect(type.element, typeElement);
   }
 
@@ skipping 1844 matching lines @@
 }
 
 class _FunctionTypeImplTest_isSubtypeOf_baseCase_classFunction
     extends InterfaceTypeImpl {
   _FunctionTypeImplTest_isSubtypeOf_baseCase_classFunction(ClassElement arg0)
       : super(arg0);
 
   @override
   bool get isDartCoreFunction => true;
 }