Assert that we don't mix K and J elements

pkg/compiler/lib/src/js_model/js_strategy.dart

 // Copyright (c) 2017, 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.js_model.strategy;
 
 import '../closure.dart' show ClosureConversionTask;
 import '../common/tasks.dart';
 import '../common_elements.dart';
 import '../compiler.dart';
 import '../elements/elements.dart' show TypedefElement;
 import '../elements/entities.dart';
 import '../enqueue.dart';
 import '../io/source_information.dart';
 import '../js_emitter/sorter.dart';
 import '../js/js_source_mapping.dart';
 import '../js_backend/backend.dart';
 import '../js_backend/backend_usage.dart';
 import '../js_backend/constant_system_javascript.dart';
 import '../js_backend/interceptor_data.dart';
 import '../js_backend/native_data.dart';
+import '../js_backend/runtime_types.dart';
 import '../kernel/element_map.dart';
 import '../kernel/element_map_impl.dart';
 import '../kernel/kernel_backend_strategy.dart';
 import '../kernel/kernel_strategy.dart';
 import '../ssa/ssa.dart';
 import '../universe/class_set.dart';
 import '../universe/world_builder.dart';
 import '../util/emptyset.dart';
 import '../world.dart';
 import 'closure.dart';
@@ skipping 103 matching lines @@
         <ClassEntity, Set<ClassEntity>>{};
     closedWorld.typesImplementedBySubclasses
         .forEach((ClassEntity cls, Set<ClassEntity> uses) {
       typesImplementedBySubclasses[_map.toBackendClass(cls)] =
           uses.map(_map.toBackendClass).toSet();
     });
 
     Iterable<MemberEntity> assignedInstanceMembers =
         closedWorld.assignedInstanceMembers.map(_map.toBackendMember).toList();
 
+    Iterable<ClassEntity> liveNativeClasses =
+        closedWorld.liveNativeClasses.map(_map.toBackendClass).toList();
+
+    RuntimeTypesNeed rtiNeed =
+        new JsRuntimeTypesNeed(_map, closedWorld.rtiNeed);
+
     return new JsClosedWorld(_elementMap,
         elementEnvironment: _elementEnvironment,
         dartTypes: _elementMap.types,
         commonElements: _commonElements,
         constantSystem: const JavaScriptConstantSystem(),
         backendUsage: backendUsage,
         nativeData: nativeData,
         interceptorData: interceptorData,
+        rtiNeed: rtiNeed,
         classHierarchyNodes: classHierarchyNodes,
         classSets: classSets,
         implementedClasses: implementedClasses,
+        liveNativeClasses: liveNativeClasses,
         liveInstanceMembers: liveInstanceMembers,
         assignedInstanceMembers: assignedInstanceMembers,
         mixinUses: mixinUses,
         typesImplementedBySubclasses: typesImplementedBySubclasses,
         // TODO(johnniwinther): Support this:
         allTypedefs: new ImmutableEmptySet<TypedefElement>());
   }
 
   @override
   Sorter get sorter {
@@ skipping 27 matching lines @@
       ClosedWorld closedWorld,
       SelectorConstraintsStrategy selectorConstraintsStrategy) {
     return new KernelCodegenWorldBuilder(
         elementMap,
         closedWorld.elementEnvironment,
         nativeBasicData,
         closedWorld,
         selectorConstraintsStrategy);
   }
 }
+
+class JsRuntimeTypesNeed implements RuntimeTypesNeed {
+  final JsToFrontendMap _map;
+  final RuntimeTypesNeed _rtiNeed;
+
+  JsRuntimeTypesNeed(this._map, this._rtiNeed);
+
+  @override
+  bool classNeedsRti(ClassEntity cls) {
+    return _rtiNeed.classNeedsRti(_map.toFrontendClass(cls));
+  }
+
+  @override
+  bool classUsesTypeVariableExpression(ClassEntity cls) {
+    return _rtiNeed.classUsesTypeVariableExpression(_map.toFrontendClass(cls));
+  }
+
+  @override
+  bool localFunctionNeedsRti(Local function) {
+    throw new UnimplementedError('JsRuntimeTypesNeed.localFunctionNeedsRti');
+  }
+
+  @override
+  bool methodNeedsRti(FunctionEntity function) {
+    return _rtiNeed.methodNeedsRti(_map.toFrontendMember(function));
+  }
+
+  @override
+  bool classNeedsRtiField(ClassEntity cls) {
+    return _rtiNeed.classNeedsRtiField(_map.toFrontendClass(cls));
+  }
+}