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 // Debugger.Frame preserves Ion frame identity

 load(libdir + "jitopts.js");

 if (!jitTogglesMatch(Opts_Ion2NoParallelCompilation))

   quit();

 withJitOptions(Opts_Ion2NoParallelCompilation, function () {

   var g = newGlobal();

   var dbg1 = new Debugger;

   var dbg2 = new Debugger;

   g.toggle = function toggle(x, d) {

     if (d) {

       dbg1.addDebuggee(g);

       dbg2.addDebuggee(g);

       var frame1 = dbg1.getNewestFrame();

       assertEq(frame1.environment.getVariable("x"), x);

       assertEq(frame1.implementation, "ion");

       frame1.environment.setVariable("x", "not 42");

       assertEq(dbg2.getNewestFrame().environment.getVariable("x"), "not 42");

     }

   };

   g.eval("" + function f(x, d) { toggle(x, d); });

   g.eval("(" + function test() {

     for (var i = 0; i < 5; i++)

       f(42, false);

     f(42, true);

   } + ")();");

 });