Move WorldImpact to universe/world_impact.dart

pkg/compiler/lib/src/deferred_load.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.
 
 library deferred_load;
 
 import 'common.dart';
 import 'common/backend_api.dart' show
     Backend;
 import 'common/tasks.dart' show
@@ skipping 14 matching lines @@
     ElementKind,
     Elements,
     ExportElement,
     FunctionElement,
     ImportElement,
     LibraryElement,
     MetadataAnnotation,
     PrefixElement,
     ScopeContainerElement,
     TypedefElement;
-import 'enqueue.dart' show
-    WorldImpact;
 import 'js_backend/js_backend.dart' show
     JavaScriptBackend;
 import 'resolution/resolution.dart' show
     AnalyzableElementX;
 import 'resolution/tree_elements.dart' show
     TreeElements;
 import 'tree/tree.dart' as ast;
 import 'tree/tree.dart' show
     Import,
     LibraryTag,
     LibraryDependency,
     LiteralDartString,
     LiteralString,
     NewExpression,
     Node;
+import 'universe/world_impact.dart' show
+    WorldImpact;
 import 'util/setlet.dart' show
     Setlet;
 import 'util/uri_extras.dart' as uri_extras;
 import 'util/util.dart' show
     Link, makeUnique;
 
 /// A "hunk" of the program that will be loaded whenever one of its [imports]
 /// are loaded.
 ///
 /// Elements that are only used in one deferred import, is in an OutputUnit with
@@ skipping 918 matching lines @@
     return result;
   }
 
   bool operator ==(other) {
     if (other is! _DeclaredDeferredImport) return false;
     return declaration == other.declaration;
   }
 
   int get hashCode => declaration.hashCode * 17;
 }