Provide a way to get a Type back from a ClassMirror.

runtime/lib/mirrors_impl.dart

 // Copyright (c) 2012, 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.
 
 // VM-specific implementation of the dart:mirrors library.
 
 import "dart:collection";
 
 // These values are allowed to be passed directly over the wire.
 bool _isSimpleValue(var value) {
@@ skipping 351 matching lines @@
   _LocalClassMirrorImpl(reflectee,
                         this._reflectedType,
                         String simpleName,
                         this._isGeneric)
       : this._simpleName = _s(simpleName),
         super(reflectee);
 
   final Type _reflectedType;
   final bool _isGeneric;
 
+  bool get hasReflectedType => _reflectedType != null;
+  Type get reflectedType {
+    if (!hasReflectedType) {
+      throw new UnsupportedError(
+          "Declarations of generics have no reflected type");
+    }
+    return _reflectedType;
+  }
+
   Symbol _simpleName;
   Symbol get simpleName {
     // dynamic, void and the function types have their names set eagerly in the
     // constructor.
     if(_simpleName == null) {
       _simpleName = _s(_name(_reflectee));
     }
     return _simpleName;
   }
 
@@ skipping 28 matching lines @@
   ClassMirror get defaultFactory => null;
 
   ClassMirror _superclass;
   ClassMirror get superclass {
     if (_superclass == null) {
       Type supertype = _supertype(_reflectee);
       if (supertype == null) {
         // Object has no superclass.
         return null;
       }
-      _superclass = reflectClass(supertype);
+      _superclass = _Mirrors._reflectType(supertype);
     }
     return _superclass;
   }
 
   var _superinterfaces;
   List<ClassMirror> get superinterfaces {
     if (_superinterfaces == null) {
       _superinterfaces = _interfaces(_reflectee)
           .map((i) => reflectClass(i)).toList(growable:false);
     }
@@ skipping 779 matching lines @@
     if (typeMirror == null) {
       typeMirror = makeLocalTypeMirror(key);
       _instanitationCache[key] = typeMirror;
       if (typeMirror is ClassMirror && !typeMirror._isGeneric) {
         _declarationCache[key] = typeMirror;
       }
     }
     return typeMirror;
   }
 }