Make unique id to all scripts work with snapshot

src/factory.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 135 matching lines @@
 
 Handle<AccessorInfo> Factory::NewAccessorInfo() {
   Handle<AccessorInfo> info =
       Handle<AccessorInfo>::cast(NewStruct(ACCESSOR_INFO_TYPE));
   info->set_flag(0);  // Must clear the flag, it was initialized as undefined.
   return info;
 }
 
 
 Handle<Script> Factory::NewScript(Handle<String> source) {
-  static uint32_t next_id = 1;
-
+  // Generate id for this script.
+  int id;
+  if (Heap::last_script_id()->IsUndefined()) {
+    // Script ids start from one.
+    id = 1;
+  } else {
+    // Increment id, wrap when positive smi is exhausted.
+    id = Smi::cast(Heap::last_script_id())->value();
+    id++;
+    if (!Smi::IsValid(id)) {
+      id = 0;
+    }
+  }
+  Heap::SetLastScriptId(Smi::FromInt(id));
+  
+  // Create and initialize script object.
   Handle<Script> script = Handle<Script>::cast(NewStruct(SCRIPT_TYPE));
   script->set_source(*source);
   script->set_name(Heap::undefined_value());
-  script->set_id(*Factory::NewNumberFromUint(next_id++));
+  script->set_id(Heap::last_script_id());
   script->set_line_offset(Smi::FromInt(0));
   script->set_column_offset(Smi::FromInt(0));
   script->set_type(Smi::FromInt(SCRIPT_TYPE_NORMAL));
   script->set_wrapper(*Factory::NewProxy(0, TENURED));
   script->set_line_ends(Heap::undefined_value());
+
   return script;
 }
 
 
 Handle<Proxy> Factory::NewProxy(Address addr, PretenureFlag pretenure) {
   CALL_HEAP_FUNCTION(Heap::AllocateProxy(addr, pretenure), Proxy);
 }
 
 
 Handle<Proxy> Factory::NewProxy(const AccessorDescriptor* desc) {
@@ skipping 683 matching lines @@
     Execution::ConfigureInstance(instance,
                                  instance_template,
                                  pending_exception);
   } else {
     *pending_exception = false;
   }
 }
 
 
 } }  // namespace v8::internal