Added %FlattenString and use it to speed up a regression test.

src/runtime.h

 // Copyright 2012 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 356 matching lines @@
   F(InitializeConstGlobal, 2, 1) \
   F(InitializeConstContextSlot, 3, 1) \
   F(OptimizeObjectForAddingMultipleProperties, 2, 1) \
   \
   /* Debugging */ \
   F(DebugPrint, 1, 1) \
   F(DebugTrace, 0, 1) \
   F(TraceEnter, 0, 1) \
   F(TraceExit, 1, 1) \
   F(Abort, 2, 1) \
+  F(FlattenString, 1, 1) \

[Michael Starzinger, 2013/01/09 09:09:40]

Nit of the day: I think this better fits into the /* Utilities */ category
further up.

[Sven Panne, 2013/01/09 09:28:42]

Done.

   /* Logging */ \
   F(Log, 2, 1) \
   /* ES5 */ \
   F(LocalKeys, 1, 1) \
   /* Cache suport */ \
   F(GetFromCache, 2, 1) \
   \
   /* Message objects */ \
   F(MessageGetStartPosition, 1, 1) \
   F(MessageGetScript, 1, 1) \
@@ skipping 335 matching lines @@
 //---------------------------------------------------------------------------
 // Constants used by interface to runtime functions.
 
 class DeclareGlobalsEvalFlag:     public BitField<bool,         0, 1> {};
 class DeclareGlobalsNativeFlag:   public BitField<bool,         1, 1> {};
 class DeclareGlobalsLanguageMode: public BitField<LanguageMode, 2, 2> {};
 
 } }  // namespace v8::internal
 
 #endif  // V8_RUNTIME_H_