Make full_emitter parts into libraries

pkg/compiler/lib/src/js_emitter/full_emitter/class_builder.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.
 
-part of dart2js.js_emitter.full_emitter;
+library dart2js.js_emitter.full_emitter.class_builder;
+
+import '../../elements/elements.dart'
+    show
+    ClassElement,
+    Element;
+import '../../js/js.dart' as jsAst;
+import '../../js/js.dart' show js;
+import '../../js_backend/js_backend.dart'
+    show
+    Namer;
 
 /**
  * A data structure for collecting fragments of a class definition.
  */
 class ClassBuilder {
   final List<jsAst.Property> properties = <jsAst.Property>[];
   final List<jsAst.Literal> fields = <jsAst.Literal>[];
 
   jsAst.Name superName;
   jsAst.Node functionType;
@@ skipping 65 matching lines @@
       fieldsAndProperties = <jsAst.Property>[];
       fieldsAndProperties.add(new jsAst.Property(
           js.string(namer.classDescriptorProperty), classData));
       fieldsAndProperties.addAll(properties);
     } else {
       fieldsAndProperties = properties;
     }
     return new jsAst.ObjectInitializer(fieldsAndProperties, isOneLiner: false);
   }
 }