Revert "Move dart2jslib parts into separate libraries."

pkg/compiler/lib/src/world.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.world;
-
-import 'closure.dart' show
-    SynthesizedCallMethodElementX;
-import 'dart2jslib.dart' show
-    invariant,
-    Backend,
-    Compiler,
-    Registry;
-import 'dart_types.dart';
-import 'elements/elements.dart' show
-    ClassElement,
-    Element,
-    FunctionElement,
-    MixinApplicationElement,
-    TypedefElement,
-    VariableElement;
-import 'ordered_typeset.dart';
-import 'types/types.dart' as ti;
-import 'universe/universe.dart' show
-    FunctionSet,
-    Selector,
-    SideEffects;
-import 'universe/class_set.dart';
-import 'util/util.dart' show
-    Link;
+part of dart2js;
 
 abstract class ClassWorld {
   // TODO(johnniwinther): Refine this into a `BackendClasses` interface.
   Backend get backend;
 
   // TODO(johnniwinther): Remove the need for this getter.
   @deprecated
   Compiler get compiler;
 
   /// The [ClassElement] for the [Object] class defined in 'dart:core'.
@@ skipping 528 matching lines @@
     functionsThatMightBePassedToApply.add(element);
   }
 
   bool getMightBePassedToApply(Element element) {
     // We have to check whether the element we look at was created after
     // type inference ran. This is currently only the case for the call
     // method of function classes that were generated for function
     // expressions. In such a case, we have to look at the original
     // function expressions's element.
     // TODO(herhut): Generate classes for function expressions earlier.
-    if (element is SynthesizedCallMethodElementX) {
+    if (element is closureMapping.SynthesizedCallMethodElementX) {
       return getMightBePassedToApply(element.expression);
     }
     return functionsThatMightBePassedToApply.contains(element);
   }
 
   bool get hasClosedWorldAssumption => !compiler.hasIncrementalSupport;
 }