Improve Hydrogen code for accessing undefined/null/Infinity.

src/factory.h

 // Copyright 2011 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 426 matching lines @@
                          Handle<Object> match_pattern);
 
   // Creates a new FixedArray that holds the data associated with the
   // irregexp regexp and stores it in the regexp.
   void SetRegExpIrregexpData(Handle<JSRegExp> regexp,
                              JSRegExp::Type type,
                              Handle<String> source,
                              JSRegExp::Flags flags,
                              int capture_count);
 
+  // Returns the value for a known global constant (a property of the global
+  // object which is neither configurable nor writable) like 'undefined'.
+  // Returns a null handle when the given name is unknown.
+  Handle<Object> GlobalConstantFor(Handle<String> name);
+
  private:
   Isolate* isolate() { return reinterpret_cast<Isolate*>(this); }
 
   Handle<JSFunction> NewFunctionHelper(Handle<String> name,
                                        Handle<Object> prototype);
 
   Handle<JSFunction> NewFunctionWithoutPrototypeHelper(
       Handle<String> name,
       StrictModeFlag strict_mode);
 
   Handle<DescriptorArray> CopyAppendCallbackDescriptors(
       Handle<DescriptorArray> array,
       Handle<Object> descriptors);
 
   // Create a new map cache.
   Handle<MapCache> NewMapCache(int at_least_space_for);
 
   // Update the map cache in the global context with (keys, map)
   Handle<MapCache> AddToMapCache(Handle<Context> context,
                                  Handle<FixedArray> keys,
                                  Handle<Map> map);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_FACTORY_H_