Create ClassElement.type lazily in ClassElementImpl and EnumElementImpl.

pkg/analyzer/test/generated/resolver_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.
 
 library analyzer.test.generated.resolver_test;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 2904 matching lines @@
     InterfaceType mockStreamType = mockAsyncLib.getType('Stream').type;
     expect(provider.streamType, same(mockStreamType));
     expect(provider.typeType, same(typeType));
   }
 
   ClassElement _classElement(String typeName, InterfaceType superclassType,
       [List<String> parameterNames]) {
     ClassElementImpl element =
         new ClassElementImpl.forNode(AstFactory.identifier3(typeName));
     element.supertype = superclassType;
-    InterfaceTypeImpl type = new InterfaceTypeImpl(element);
-    element.type = type;
     if (parameterNames != null) {
       int count = parameterNames.length;
       if (count > 0) {
         List<TypeParameterElementImpl> typeParameters =
             new List<TypeParameterElementImpl>(count);
         List<TypeParameterTypeImpl> typeArguments =
             new List<TypeParameterTypeImpl>(count);
         for (int i = 0; i < count; i++) {
           TypeParameterElementImpl typeParameter =
               new TypeParameterElementImpl.forNode(
                   AstFactory.identifier3(parameterNames[i]));
           typeParameters[i] = typeParameter;
           typeArguments[i] = new TypeParameterTypeImpl(typeParameter);
           typeParameter.type = typeArguments[i];
         }
         element.typeParameters = typeParameters;
-        type.typeArguments = typeArguments;
       }
     }
     return element;
   }
 }
 
 @reflectiveTest
 class TypeResolverVisitorTest {
   /**
    * The error listener to which errors will be reported.
@@ skipping 646 matching lines @@
  */
 class _StaleElement extends ElementImpl {
   _StaleElement() : super("_StaleElement", -1);
 
   @override
   get kind => throw "_StaleElement's kind shouldn't be accessed";
 
   @override
   accept(_) => throw "_StaleElement shouldn't be visited";
 }