Toward precompiled snapshots.

runtime/vm/snapshot_ids.h

 // 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.
 
 #ifndef VM_SNAPSHOT_IDS_H_
 #define VM_SNAPSHOT_IDS_H_
 
 #include "vm/raw_object.h"
 
 namespace dart {
 
 // Index for predefined singleton objects used in a snapshot.
 enum {
   kNullObject = 0,
   kSentinelObject,
+  kTransitionSentinelObject,

[rmacnak, 2015/08/13 00:56:22]

Referenced from field initializer functions.

   kEmptyArrayObject,
   kZeroArrayObject,
   kTrueValue,
   kFalseValue,
   // Marker for special encoding of double objects in message snapshots.
   kDoubleObject,
   // Object id has been optimized away; reader should use next available id.
   kOmittedObjectId,
 
   kClassIdsOffset = kOmittedObjectId,
@@ skipping 17 matching lines @@
 
   kInstanceObjectId,
   kStaticImplicitClosureObjectId,
   kMaxPredefinedObjectIds,
   kInvalidIndex = -1,
 };
 
 }  // namespace dart
 
 #endif  // VM_SNAPSHOT_IDS_H_