Fix canonicalization of types.

runtime/vm/isolate.h

 // 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.
 
 #ifndef VM_ISOLATE_H_
 #define VM_ISOLATE_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/thread.h"
@@ skipping 66 matching lines @@
 #define REUSABLE_HANDLE_LIST(V)                                                \
   V(Array)                                                                     \
   V(Class)                                                                     \
   V(Error)                                                                     \
   V(Field)                                                                     \
   V(Function)                                                                  \
   V(Instance)                                                                  \
   V(Object)                                                                    \
   V(String)                                                                    \
   V(TypeArguments)                                                             \
+  V(AbstractType)                                                              \
   V(TypeParameter)                                                             \
 
 class Isolate : public BaseIsolate {
  public:
   ~Isolate();
 
   static inline Isolate* Current() {
     return reinterpret_cast<Isolate*>(Thread::GetThreadLocal(isolate_key));
   }
 
@@ skipping 558 matching lines @@
   char* script_url_;
   char* library_url_;
   char* class_name_;
   char* function_name_;
   char* exception_callback_name_;
 };
 
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_