Add a limited version of ParameterMirrors that can only tell whether they are

runtime/lib/mirrors_impl.dart

Index: runtime/lib/mirrors_impl.dart
===================================================================
--- runtime/lib/mirrors_impl.dart	(revision 9669)
+++ runtime/lib/mirrors_impl.dart	(working copy)
@@ -183,7 +183,6 @@
     implements InstanceMirror {
   _LocalInstanceMirrorImpl(ref,
                            this._class,
-                           this._hasSimpleValue,
                            this._reflectee) : super(ref) {}
 
   var _class;
@@ -197,12 +196,11 @@
   // LocalInstanceMirrors always reflect local instances
   bool hasReflectee = true; 
 
-  var _hasSimpleValue;
   var _reflectee;
   get reflectee() => _reflectee;
 
   String toString() {
-    if (_hasSimpleValue) {
+    if (isSimpleValue(_reflectee)) {
       if (_reflectee is String) {
         return "InstanceMirror on <'${_dartEscape(_reflectee)}'>";
       } else {
@@ -372,6 +370,7 @@
     implements MethodMirror {
   _LocalMethodMirrorImpl(this.simpleName,
                          this._owner,
+                         this._parameters,
                          this.isStatic,
                          this.isAbstract,
                          this.isGetter,
@@ -412,11 +411,29 @@
   final bool isRedirectingConstructor;
   final bool isFactoryConstructor;
 
+  List<ParameterMirror> _parameters;
+  List<ParameterMirror> parameters() => _parameters;
+
   String toString() {
     return "MethodMirror on '$simpleName'";
   }
 }
 
+class _LocalParameterMirrorImpl extends _LocalVariableMirrorImpl
+    implements ParameterMirror {
+  // TODO(rmacnak): Fill these mirrors will real information
+  _LocalParameterMirrorImpl(this._isOptional) 
+    : super(null, null, false, false) {}
+
+  
+  bool _isOptional;
+
+  TypeMirror type() => null;
+  String defaultValue() => null;
+  bool hasDefaultValue() => null;
+  bool isOptional() => _isOptional;
+}
+
 class _LocalVariableMirrorImpl extends _LocalMirrorImpl
     implements VariableMirror {
   _LocalVariableMirrorImpl(this.simpleName,