src/third_party/mozjs-45/js/src/jit-test/tests/basic/testGlobalProtoAccess.js

function testGlobalProtoAccess() {
    return "ok";
}
this.__proto__.a = 3; for (var j = 0; j < 4; ++j) { [a]; }
assertEq(testGlobalProtoAccess(), "ok");