Introduce TypedefEntity

pkg/compiler/lib/src/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 '../common.dart';
 import '../common/resolution.dart' show Resolution;
 import '../constants/constructors.dart';
 import '../constants/expressions.dart';
@@ skipping 1037 matching lines @@
 
   /// Import that declared this deferred prefix.
   ImportElement get deferredImport;
 
   /// The `loadLibrary` getter implicitly defined on deferred prefixes.
   GetterElement get loadLibrary;
 }
 
 /// A type alias definition.
 abstract class TypedefElement extends Element
-    implements AstElement, TypeDeclarationElement, FunctionTypedElement {
+    implements
+        AstElement,
+        TypeDeclarationElement,
+        FunctionTypedElement,
+        TypedefEntity {
   /// The type defined by this typedef with the type variables as its type
   /// arguments.
   ///
   /// For instance `F<T>` for `typedef void F<T>(T t)`.
   ResolutionTypedefType get thisType;
 
   /// The type defined by this typedef with `dynamic` as its type arguments.
   ///
   /// For instance `F<dynamic>` for `typedef void F<T>(T t)`.
   ResolutionTypedefType get rawType;
@@ skipping 831 matching lines @@
   /// by a field.
   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;
 }