Improve SeqStringSetChar implementation.

src/codegen.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 95 matching lines @@
                                   Label* fail);
   static void GenerateDoubleToObject(MacroAssembler* masm,
                                      AllocationSiteMode mode,
                                      Label* fail);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ElementsTransitionGenerator);
 };
 
 
-class SeqStringSetCharGenerator : public AllStatic {
- public:
-  static void Generate(MacroAssembler* masm,
-                       String::Encoding encoding,
-                       Register string,
-                       Register index,
-                       Register value);
- private:
-  DISALLOW_COPY_AND_ASSIGN(SeqStringSetCharGenerator);
-};
-
-
 } }  // namespace v8::internal
 
 #endif  // V8_CODEGEN_H_