The Tor Browser / file revision

 // arguments works in evalWithBindings (it does not interpose a function scope)

 var g = newGlobal();

 var dbg = new Debugger;

 var global = dbg.addDebuggee(g);

 var hits = 0;

 dbg.onDebuggerStatement = function (frame) {

     var argc = frame.arguments.length;

     assertEq(argc, 7);

     assertEq(frame.evalWithBindings("arguments[prop]", {prop: "length"}).return, argc);

     for (var i = 0; i < argc; i++)

         assertEq(frame.evalWithBindings("arguments[i]", {i: i}).return, frame.arguments[i]);

     hits++;

 };

 g.eval("function f() { debugger; }");

 g.eval("f(undefined, -0, NaN, '\uffff', Array.prototype, Math, f);");

 assertEq(hits, 1);