dart2js: Set the name to `null` for parameter stubs of static functions.

pkg/compiler/lib/src/js_emitter/model.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 dart2js.new_js_emitter.model;
 
 import '../js/js.dart' as js show Expression, Statement, Name, Literal,
     TokenFinalizer;
 import '../constants/values.dart' show ConstantValue;
 
@@ skipping 349 matching lines @@
   bool get needsUncheckedSetter => setterFlags != 0;
 
   bool get needsInterceptedGetter => getterFlags > 1;
   bool get needsInterceptedSetter => setterFlags > 1;
 }
 
 abstract class Method {
   /// The element should only be used during the transition to the new model.
   /// Uses indicate missing information in the model.
   final Element element;
+  /// The name of the method. If the method is a [ParameterStubMethod] for a
+  /// static function, then the name can be `null`. In that case, only the
+  /// [ParameterStubMethod.callName] should be used.
   final js.Name name;
   final js.Expression code;
 
   Method(this.element, this.name, this.code);
 }
 
 /// A method that corresponds to a method in the original Dart program.
 class DartMethod extends Method {
   final bool needsTearOff;
   final js.Name tearOffName;
@@ skipping 120 matching lines @@
               requiredParameterCount: requiredParameterCount,
               optionalParameterDefaultValues: optionalParameterDefaultValues,
               functionType: functionType);
 }
 
 class StaticStubMethod extends StubMethod implements StaticMethod {
   Holder holder;
   StaticStubMethod(js.Name name, this.holder, js.Expression code)
       : super(name, code);
 }