Track ascii-ness of data in externalized strings.

src/execution.h

 // 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 298 matching lines @@
 };
 
 
 class GCExtension : public v8::Extension {
  public:
   GCExtension() : v8::Extension("v8/gc", kSource) {}
   virtual v8::Handle<v8::FunctionTemplate> GetNativeFunction(
       v8::Handle<v8::String> name);
   static v8::Handle<v8::Value> GC(const v8::Arguments& args);
  private:
-  static const char* kSource;
+  static const char* const kSource;
 };
 
 
+class ExternalizeStringExtension : public v8::Extension {
+ public:
+  ExternalizeStringExtension() : v8::Extension("v8/externalize", kSource) {}
+  virtual v8::Handle<v8::FunctionTemplate> GetNativeFunction(
+      v8::Handle<v8::String> name);
+  static v8::Handle<v8::Value> Externalize(const v8::Arguments& args);
+  static v8::Handle<v8::Value> IsAscii(const v8::Arguments& args);
+ private:
+  static const char* const kSource;
+};
+
 } }  // namespace v8::internal
 
 #endif  // V8_EXECUTION_H_