Make the universe parts into small libraries.

pkg/compiler/lib/src/inferrer/simple_types_inferrer.dart

 // Copyright (c) 2013, 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 simple_types_inferrer;
 
 import '../closure.dart' show
     ClosureClassMap,
     ClosureScope;
 import '../common/names.dart' show
@@ skipping 24 matching lines @@
     FlatTypeMask,
     TypeMask,
     ContainerTypeMask,
     ElementTypeMask,
     ValueTypeMask,
     TypeSystem,
     MinimalInferrerEngine;
 import '../util/util.dart' show
     Link,
     Setlet;
-import '../universe/universe.dart' show
-    CallStructure,
-    Selector,
+import '../universe/call_structure.dart' show
+    CallStructure;
+import '../universe/selector.dart' show
+    Selector;
+import '../universe/side_effects.dart' show
     SideEffects;
 import '../world.dart' show ClassWorld;
 
 import 'inferrer_visitor.dart';
 
 /**
  * An implementation of [TypeSystem] for [TypeMask].
  */
 class TypeMaskSystem implements TypeSystem<TypeMask> {
   final Compiler compiler;
@@ skipping 2260 matching lines @@
     TypeMask moveNextMask = elements.getMoveNextTypeMask(node);
 
     T iteratorType = handleDynamicSend(
         node, iteratorSelector, iteratorMask, expressionType,
         new ArgumentsTypes<T>.empty());
 
     return handleForInLoop(node, iteratorType, currentSelector, currentMask,
                            moveNextSelector, moveNextMask);
   }
 }