Move dart_types to elements/resolution_types

pkg/compiler/lib/src/common/backend_api.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 dart2js.backend_api;
 
 import 'dart:async' show Future;
 
 import '../common.dart';
 import '../common/codegen.dart' show CodegenImpact;
 import '../common/resolution.dart' show ResolutionImpact, Frontend, Target;
 import '../compile_time_constants.dart'
     show BackendConstantEnvironment, ConstantCompilerTask;
 import '../compiler.dart' show Compiler;
 import '../constants/constant_system.dart' show ConstantSystem;
 import '../constants/expressions.dart' show ConstantExpression;
 import '../constants/values.dart' show ConstantValue;
-import '../dart_types.dart' show DartType, InterfaceType;
+import '../elements/resolution_types.dart' show DartType, InterfaceType;
 import '../elements/elements.dart'
     show
         ClassElement,
         Element,
         FunctionElement,
         MemberElement,
         MethodElement,
         LibraryElement;
 import '../elements/entities.dart';
 import '../enqueue.dart' show Enqueuer, EnqueueTask, ResolutionEnqueuer;
@@ skipping 385 matching lines @@
   ClassElement get asyncStarStreamImplementation;
   ClassElement get indexableImplementation;
   ClassElement get mutableIndexableImplementation;
   ClassElement get indexingBehaviorImplementation;
   ClassElement get interceptorImplementation;
 
   bool isDefaultEqualityImplementation(Element element);
   bool isInterceptorClass(ClassElement cls);
   bool isNative(Element element);
 }