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.
 
-part of dart2js;
+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;
 
 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 closureMapping.SynthesizedCallMethodElementX) {
+    if (element is SynthesizedCallMethodElementX) {
       return getMightBePassedToApply(element.expression);
     }
     return functionsThatMightBePassedToApply.contains(element);
   }
 
   bool get hasClosedWorldAssumption => !compiler.hasIncrementalSupport;
 }