[snapshot] serialize embedder-provided external references.

src/heap/heap.cc

 // Copyright 2012 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.
 
 #include "src/heap/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/scopeinfo.h"
 #include "src/base/bits.h"
@@ skipping 2852 matching lines @@
 
   Handle<SeededNumberDictionary> slow_element_dictionary =
       SeededNumberDictionary::New(isolate(), 0, TENURED);
   slow_element_dictionary->set_requires_slow_elements();
   set_empty_slow_element_dictionary(*slow_element_dictionary);
 
   set_materialized_objects(*factory->NewFixedArray(0, TENURED));
 
   // Handling of script id generation is in Heap::NextScriptId().
   set_last_script_id(Smi::FromInt(v8::UnboundScript::kNoScriptId));
+  set_next_template_serial_number(Smi::FromInt(0));
 
   // Allocate the empty script.
   Handle<Script> script = factory->NewScript(factory->empty_string());
   script->set_type(Script::TYPE_NATIVE);
   set_empty_script(*script);
 
   Handle<PropertyCell> cell = factory->NewPropertyCell();
   cell->set_value(Smi::FromInt(Isolate::kArrayProtectorValid));
   set_array_protector(*cell);
 
@@ skipping 3571 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8