Register synthesized mixin application classes in the library and reuse them

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";
 
 final emptyList = new UnmodifiableListView([]);
 final emptyMap = new _UnmodifiableMapView({});
@@ skipping 556 matching lines @@
     return _s(
       _n(klass.qualifiedName)
       + ' with '
       + mixins.reversed.map((m)=>_n(m.qualifiedName)).join(', '));
   }
 
   var _mixin;
   ClassMirror get mixin {
     if (_mixin == null) {
       if (_isMixinTypedef) {
-        Type mixinType = isOriginalDeclaration
-            ? _nativeMixin(_trueSuperclass._reflectedType)
-            : _nativeMixinInstantiated(_trueSuperclass._reflectedType, _instantiator);
+        Type mixinType = _nativeMixinInstantiated(_trueSuperclass._reflectedType,
+                                                  _instantiator);
         _mixin = reflectType(mixinType);
       } else {
-        Type mixinType = isOriginalDeclaration
-            ? _nativeMixin(_reflectedType)
-            : _nativeMixinInstantiated(_reflectedType, _instantiator);
+        Type mixinType = _nativeMixinInstantiated(_reflectedType, _instantiator);
         if (mixinType == null) {
           // The reflectee is not a mixin application.
           _mixin = this;
         } else {
           _mixin = reflectType(mixinType);
         }
       }
     }
     return _mixin;
   }
@@ skipping 934 matching lines @@
     if (typeMirror == null) {
       typeMirror = makeLocalTypeMirror(key);
       _instanitationCache[key] = typeMirror;
       if (typeMirror is ClassMirror && !typeMirror._isGeneric) {
         _declarationCache[key] = typeMirror;
       }
     }
     return typeMirror;
   }
 }