Change js_emitter parts into libraries

pkg/compiler/lib/src/js_emitter/parameter_stub_generator.dart

Index: pkg/compiler/lib/src/js_emitter/parameter_stub_generator.dart
diff --git a/pkg/compiler/lib/src/js_emitter/parameter_stub_generator.dart b/pkg/compiler/lib/src/js_emitter/parameter_stub_generator.dart
index 81467cc7372e23c1603d907ad168c6c4d4618916..e91bcdd217c6532afb108a03e731e1ec52b845f4 100644
--- a/pkg/compiler/lib/src/js_emitter/parameter_stub_generator.dart
+++ b/pkg/compiler/lib/src/js_emitter/parameter_stub_generator.dart
@@ -2,7 +2,36 @@
 // 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;
+library dart2js.js_emitter.parameter_stub_generator;
+
+import '../closure.dart'
+    show ClosureClassElement;
+import '../common.dart';
+import '../compiler.dart' show Compiler;
+import '../constants/values.dart';
+import '../elements/elements.dart'
+    show
+    ClassElement,
+    FunctionElement,
+    FunctionSignature,
+    MethodElement,
+    ParameterElement;
+import '../js/js.dart' as jsAst;
+import '../js/js.dart' show js;
+import '../js_backend/js_backend.dart'
+    show
+    JavaScriptBackend,
+    JavaScriptConstantCompiler,
+    Namer;
+import '../universe/call_structure.dart' show CallStructure;
+import '../universe/selector.dart' show Selector;
+import '../universe/world_builder.dart'
+    show SelectorConstraints;
+import '../world.dart' show ClosedWorld;
+
+import 'model.dart';
+
+import 'code_emitter_task.dart' show CodeEmitterTask, Emitter;
 
 class ParameterStubGenerator {
   static final Set<Selector> emptySelectorSet = new Set<Selector>();