Use entities in some full_emitter sublibraries

pkg/compiler/lib/src/js_backend/backend.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 js_backend.backend;
 
 import 'dart:async' show Future;
 
 import 'package:js_runtime/shared/embedded_names.dart' as embeddedNames;
 
@@ skipping 1973 matching lines @@
    * accessed (invoked, get, set) that is not accessible for the reflective
    * system.
    */
   bool isAccessibleByReflection(Element element) {
     if (element.isClass) {
       element = getDartClass(element);
     }
     return membersNeededForReflection.contains(element);
   }
 
+  bool isMemberAccessibleByReflection(MemberElement element) {
+    return membersNeededForReflection.contains(element);
+  }
+
   /**
    * Returns true if the element has to be resolved due to a mirrorsUsed
    * annotation. If we have insufficient mirrors used annotations, we only
    * keep additional elements if treeshaking has been disabled.
    */
   bool requiredByMirrorSystem(Element element) {
     return hasInsufficientMirrorsUsed && isTreeShakingDisabled ||
         matchesMirrorsMetaTarget(element) ||
         targetsUsed.contains(element);
   }
@@ skipping 1292 matching lines @@
   @override
   bool isNativeClass(ClassElement element) {
     return helpers.backend.isNative(element);
   }
 
   @override
   bool isNativeMember(MemberElement element) {
     return helpers.backend.isNative(element);
   }
 }