Use entities in BackendClasses

pkg/compiler/lib/src/native/enqueue.dart

 // Copyright (c) 2014, 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.
 
 import 'dart:collection' show Queue;
 
 import '../common.dart';
 import '../common/backend_api.dart' show ForeignResolver;
 import '../common/resolution.dart' show Resolution;
 import '../compiler.dart' show Compiler;
@@ skipping 419 matching lines @@
     int unusedBefore = _unusedClasses.length;
     Set<ClassElement> matchingClasses = new Set<ClassElement>();
     for (var type in behavior.typesInstantiated) {
       if (type is SpecialType) {
         if (type == SpecialType.JsObject) {
           registerInstantiation(compiler.commonElements.objectType);
         }
         continue;
       }
       if (type is ResolutionInterfaceType) {
-        if (type == commonElements.intType) {
-          registerInstantiation(type);
-        } else if (type == commonElements.doubleType) {
-          registerInstantiation(type);
-        } else if (type == commonElements.numType) {
+        if (type == commonElements.numType) {
           registerInstantiation(commonElements.doubleType);
           registerInstantiation(commonElements.intType);
-        } else if (type == commonElements.stringType) {
-          registerInstantiation(type);
-        } else if (type == commonElements.nullType) {
-          registerInstantiation(type);
-        } else if (type == commonElements.boolType) {
-          registerInstantiation(type);
-        } else if (compiler.types.isSubtype(
-            type, backend.backendClasses.listImplementation.rawType)) {
+        } else if (type == commonElements.intType ||
+            type == commonElements.doubleType ||
+            type == commonElements.stringType ||
+            type == commonElements.nullType ||
+            type == commonElements.boolType ||
+            type.asInstanceOf(backend.backendClasses.listClass) != null) {
           registerInstantiation(type);
         }
         // TODO(johnniwinther): Improve spec string precision to handle type
         // arguments and implements relations that preserve generics. Currently
         // we cannot distinguish between `List`, `List<dynamic>`, and
         // `List<int>` and take all to mean `List<E>`; in effect not including
         // any native subclasses of generic classes.
         // TODO(johnniwinther,sra): Find and replace uses of `List` with the
         // actual implementation classes such as `JSArray` et al.
         matchingClasses
@@ skipping 189 matching lines @@
     List<ClassEntity> directSubtypes =
         emitter.directSubtypes.putIfAbsent(superclass, () => <ClassEntity>[]);
     directSubtypes.add(cls);
   }
 
   void logSummary(log(message)) {
     log('Compiled ${_registeredClasses.length} native classes, '
         '${_unusedClasses.length} native classes omitted.');
   }
 }