Fix Initialize & Dispose for external snapshot.

src/snapshot-empty.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Used for building without snapshots.
 
 #include "src/v8.h"
 
 #include "src/snapshot.h"
 
 namespace v8 {
 namespace internal {
 
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
 // Dummy implementations of Set*FromFile(..) APIs.
 //
 // These are meant for use with snapshot-external.cc. Should this file
 // be compiled with those options we just supply these dummy implementations
 // below. This happens when compiling the mksnapshot utility.
 void SetNativesFromFile(StartupData* data) { CHECK(false); }
 void SetSnapshotFromFile(StartupData* data) { CHECK(false); }
+void ReadNatives() {}
 void DisposeNatives() {}
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 
 
 const v8::StartupData* Snapshot::DefaultSnapshotBlob() { return NULL; }
 } }  // namespace v8::internal