function foo(a) { return arguments[1] + (function() { return a * 101; })(); } noInline(foo); for (var i = 0; i < 10000; ++i) { var result = foo(42, 97); if (result != 4339) throw "Error: bad result: " + result; } Object.prototype[1] = 111; var result = foo(42); if (result != 4353) throw "Error: bad result at end: " + result;