Extract ResolutionWorldBuilderBase from ElementResolutionWorldBuilder

pkg/compiler/lib/src/js_backend/mirrors_data.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.
 
 import '../closure.dart';
 import '../common.dart';
 import '../common_elements.dart';
 import '../compiler.dart';
 import '../constants/values.dart';
 import '../elements/elements.dart';
@@ skipping 640 matching lines @@
           foundClosure = true;
         }
       }
     }
     // As we do not think about closures as classes, yet, we have to make sure
     // their superclasses are available for reflection manually.
     if (foundClosure) {
       ClassElement cls = _helpers.closureClass;
       _classesNeededForReflection.add(cls);
     }
-    Set<MethodElement> closurizedMembers = worldBuilder.closurizedMembers;
+    Set<FunctionEntity> closurizedMembers = worldBuilder.closurizedMembers;
     if (closurizedMembers.any(_membersNeededForReflection.contains)) {
       ClassElement cls = _helpers.boundClosureClass;
       _classesNeededForReflection.add(cls);
     }
     // Add typedefs.
     _typedefsNeededForReflection.addAll(
         closedWorld.allTypedefs.where(isTypedefReferencedFromMirrorSystem));
     // Register all symbols of reflectable elements
     for (ClassElement element in _classesNeededForReflection) {
       symbolsUsed.add(element.name);
@@ skipping 21 matching lines @@
   }
 
   /// Called when `const Symbol(name)` is seen.
   void registerConstSymbol(String name) {
     symbolsUsed.add(name);
     if (name.endsWith('=')) {
       symbolsUsed.add(name.substring(0, name.length - 1));
     }
   }
 }