Add ParameterMirror.isInitializingFormal to dart:mirrors

sdk/lib/_internal/js_runtime/lib/js_helper.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 _js_helper;
 
 import 'dart:_js_embedded_names' show
     DEFERRED_LIBRARY_URIS,
     DEFERRED_LIBRARY_HASHES,
     GET_TYPE_FROM_NAME,
@@ skipping 596 matching lines @@
 
   List<int> parameterMetadataAnnotations(int parameter) {
     if (!JS_GET_FLAG('MUST_RETAIN_METADATA')) {
       throw new StateError('metadata has not been preserved');
     } else {
       return JS('', '#[2 * # + # + # + 1]', data, parameter,
           optionalParameterCount, FIRST_DEFAULT_ARGUMENT);
     }
   }
 
+  bool isFieldInitializerParameter(int parameter) {
+    if (!JS_GET_FLAG('MUST_RETAIN_METADATA')) {
+      throw new StateError('metadata has not been preserved');
+    } else {
+      return JS('bool', '#[2 * # + 2*# + # + # + 1]', data, parameter,
+          optionalParameterCount, requiredParameterCount, FIRST_DEFAULT_ARGUMENT);
+    }
+  }
+
   int defaultValue(int parameter) {
     if (parameter < requiredParameterCount) return null;
     return JS('int', '#[# + # - #]', data,
               FIRST_DEFAULT_ARGUMENT, parameter, requiredParameterCount);
   }
 
   /// Returns the default value of the [parameter]th entry of the list of
   /// parameters sorted by name.
   int defaultValueInOrder(int parameter) {
     if (parameter < requiredParameterCount) return null;
@@ skipping 3334 matching lines @@
   throw new MainError("No top-level function named 'main'.");
 }
 
 void badMain() {
   throw new MainError("'main' is not a function.");
 }
 
 void mainHasTooManyParameters() {
   throw new MainError("'main' expects too many parameters.");
 }