Added more thread control to developer shell

src/d8.h

 // Copyright 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 74 matching lines @@
   static void MapCounters(const char* name);
   static Handle<String> ReadFile(const char* name);
   static void RunShell();
   static int Main(int argc, char* argv[]);
   static Handle<Array> GetCompletions(Handle<String> text,
                                       Handle<String> full);
   static Handle<Object> DebugMessageDetails(Handle<String> message);
   static Handle<Value> DebugCommandToJSONRequest(Handle<String> command);
 
   static Handle<Value> Print(const Arguments& args);
+  static Handle<Value> Yield(const Arguments& args);
   static Handle<Value> Quit(const Arguments& args);
   static Handle<Value> Version(const Arguments& args);
   static Handle<Value> Load(const Arguments& args);
 
   static Handle<Context> utility_context() { return utility_context_; }
 
   static const char* kHistoryFileName;
   static const char* kPrompt;
  private:
   static Persistent<Context> utility_context_;
@@ skipping 26 matching lines @@
   const char* name_;
   LineEditor* next_;
   static LineEditor* first_;
 };
 
 
 }  // namespace v8
 
 
 #endif  // V8_D8_H_