Something like this is an exit loop in "func": function test1() { function func(o) { return 0 in o; } noInline(func); let o = {__proto__:[0, 1]}; o[2] = 4; for (let i = 0; i < 10000; ++i) { func(o); } assert(func(true, o)); } test1();
<rdar://problem/86122947>