Use stack frame marker constants to mark arguments adaptor frame.

src/frames.h

 // Copyright 2006-2008 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 416 matching lines @@
 
   friend class StackFrameIterator;
 };
 
 
 // Arguments adaptor frames are automatically inserted below
 // JavaScript frames when the actual number of parameters does not
 // match the formal number of parameters.
 class ArgumentsAdaptorFrame: public JavaScriptFrame {
  public:
-  // This sentinel value is temporarily used to distinguish arguments
-  // adaptor frames from ordinary JavaScript frames. If a frame has
-  // the sentinel as its context, it is an arguments adaptor frame. It
-  // must be tagged as a small integer to avoid GC issues. Crud.
-  enum {
-    SENTINEL = (1 << kSmiTagSize) | kSmiTag,
-    NON_SENTINEL = ~SENTINEL
-  };
-
   virtual Type type() const { return ARGUMENTS_ADAPTOR; }
 
   // Determine the code for the frame.
   virtual Code* code() const;
 
   static ArgumentsAdaptorFrame* cast(StackFrame* frame) {
     ASSERT(frame->is_arguments_adaptor());
     return static_cast<ArgumentsAdaptorFrame*>(frame);
   }
 
@@ skipping 222 matching lines @@
   JavaScriptFrame* FindJavaScriptFrame(int n);
 
  private:
   StackFrameIterator iterator_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_FRAMES_H_