Support for modular mixin resolution.

pkg/kernel/lib/target/targets.dart

 // Copyright (c) 2016, 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 kernel.target.targets;
 
 import '../ast.dart';
-
+import '../core_types.dart';
+import 'flutter.dart';
 import 'vm.dart';
 import 'vmcc.dart';
-import 'flutter.dart';
 
 final List<String> targetNames = targets.keys.toList();
 
 class TargetFlags {
   bool strongMode;
   bool treeShake;
 
   TargetFlags({this.strongMode: false, this.treeShake: false});
 }
 
@@ skipping 21 matching lines @@
   /// Libraries will be loaded in order.
   List<String> get extraRequiredLibraries => <String>[];
 
   /// Additional declared variables implied by this target.
   ///
   /// These can also be passed on the command-line of form `-D<name>=<value>`,
   /// and those provided on the command-line take precedence over those defined
   /// by the target.
   Map<String, String> get extraDeclaredVariables => const <String, String>{};
 
+  /// Classes from the SDK whose interface is required for the modular
+  /// transformations.
+  Map<String, List<String>> get requiredSdkClasses => CoreTypes.requiredClasses;
+
   bool get strongMode;
 
   /// If true, the SDK should be loaded in strong mode.
   bool get strongModeSdk => strongMode;
 
   /// Perform target-specific modular transformations.
   ///
   /// These transformations should not be whole-program transformations.  They
   /// should expect that the program will contain external libraries.
   void performModularTransformations(Program program);
@@ skipping 12 matching lines @@
   final TargetFlags flags;
 
   NoneTarget(this.flags);
 
   bool get strongMode => flags.strongMode;
   String get name => 'none';
   List<String> get extraRequiredLibraries => <String>[];
   void performModularTransformations(Program program) {}
   void performGlobalTransformations(Program program) {}
 }