Make the universe parts into small libraries.

pkg/compiler/lib/src/types/types.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 types;
 
 import '../common/backend_api.dart' show
     Backend;
 import '../common/tasks.dart' show
     CompilerTask;
 import '../compiler.dart' show
     Compiler;
 import '../diagnostics/invariant.dart' show
     invariant;
 import '../diagnostics/spannable.dart' show
     NO_LOCATION_SPANNABLE;
 import '../elements/elements.dart';
-import '../inferrer/concrete_types_inferrer.dart' show ConcreteTypesInferrer;
-import '../inferrer/type_graph_inferrer.dart' show TypeGraphInferrer;
+import '../inferrer/concrete_types_inferrer.dart' show
+    ConcreteTypesInferrer;
+import '../inferrer/type_graph_inferrer.dart' show
+    TypeGraphInferrer;
 import '../tree/tree.dart';
 import '../util/util.dart';
-import '../universe/universe.dart';
+import '../universe/selector.dart' show
+    Selector;
+import '../universe/universe.dart' show
+    ReceiverMask,
+    ReceiverMaskSet,
+    UniverseReceiverMaskSet,
+    ReceiverMaskStrategy;
 import '../world.dart' show
     ClassWorld,
     World;
 
 part 'container_type_mask.dart';
 part 'dictionary_type_mask.dart';
 part 'flat_type_mask.dart';
 part 'forwarding_type_mask.dart';
 part 'map_type_mask.dart';
 part 'type_mask.dart';
@@ skipping 307 matching lines @@
           typesInferrer.getTypeOfSelector(selector, mask);
       return (concreteTypesInferrer == null)
           ? guaranteedType
           : intersection(
               guaranteedType,
               concreteTypesInferrer.getTypeOfSelector(selector, mask),
               selector);
     });
   }
 }