Update subclasses array and is_implemented bit when loading script snapshots.

runtime/vm/snapshot.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 RUNTIME_VM_SNAPSHOT_H_
 #define RUNTIME_VM_SNAPSHOT_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/bitfield.h"
@@ skipping 428 matching lines @@
 
   // Add a patch record for the object so that objects whose canonicalization
   // is deferred can be back patched after they are canonicalized.
   void AddPatchRecord(intptr_t object_id,
                       intptr_t patch_object_id,
                       intptr_t patch_offset);
 
   // Process all the deferred canonicalization entries and patch all references.
   void ProcessDeferredCanonicalizations();
 
+  // Update subclasses array and is implemented bit for interfaces/superclass in
+  // the core snapshot.
+  void FixSubclassesAndImplementors();
+
   // Decode class id from the header field.
   intptr_t LookupInternalClass(intptr_t class_header);
 
   void ArrayReadFrom(intptr_t object_id,
                      const Array& result,
                      intptr_t len,
                      intptr_t tags);
 
   intptr_t NextAvailableObjectId() const;
 
@@ skipping 551 matching lines @@
  private:
   SnapshotWriter* writer_;
   bool as_references_;
 
   DISALLOW_COPY_AND_ASSIGN(SnapshotWriterVisitor);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_SNAPSHOT_H_