Avoid patching in dart2dart.

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 '../constants/expressions.dart';
 import '../tree/tree.dart';
 import '../util/util.dart';
@@ skipping 383 matching lines @@
   ///
   /// See [:patch_parser.dart:] for a description of the terminology.
   Element get patch;
 
   /// Returns the origin for this element if this element is a patch.
   ///
   /// See [:patch_parser.dart:] for a description of the terminology.
   Element get origin;
 
   bool get isSynthesized;
-  bool get isForwardingConstructor;
   bool get isMixinApplication;
 
   bool get hasFixedBackendName;
   String get fixedBackendName;
 
   bool get isAbstract;
   bool isForeign(Backend backend);
 
   void addMetadata(MetadataAnnotation annotation);
   void setNative(String name);
@@ skipping 718 matching lines @@
   // TODO(johnniwinther): Rename to `ensureFunctionSignature`.
   @deprecated FunctionSignature computeSignature(Compiler compiler);
 
   bool get hasFunctionSignature;
 
   /// The type of this function.
   FunctionType get type;
 
   /// The synchronous/asynchronous marker on this function.
   AsyncMarker get asyncMarker;
+
+  /// `true` if this function is external.
+  bool get isExternal;
 }
 
 /// Enum for the synchronous/asynchronous function body modifiers.
 class AsyncMarker {
   /// The default function body marker.
   static AsyncMarker SYNC = const AsyncMarker._();
 
   /// The `sync*` function body marker.
   static AsyncMarker SYNC_STAR = const AsyncMarker._(isYielding: true);
 
@@ skipping 459 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;
 }