Custom call IC-s for String.prototype.{charAt,charCodeAt}.

src/x64/virtual-frame-x64.h

 // Copyright 2009 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 572 matching lines @@
   // PrepareForCall).
   Result RawCallStub(CodeStub* stub);
 
   // Calls a code object which has already been prepared for calling
   // (via PrepareForCall).
   Result RawCallCodeObject(Handle<Code> code, RelocInfo::Mode rmode);
 
   inline bool Equals(VirtualFrame* other);
 
   // Classes that need raw access to the elements_ array.
-  friend class DeferredCode;
+  friend class FrameRegisterState;
   friend class JumpTarget;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_X64_VIRTUAL_FRAME_X64_H_