Function arrow

deps/v8/test/mjsunit/harmony/json-parse-with-source.js:134–134

(k, v)

  // information for us to identify that it is an arrow function that takes only
  // two arguments.
  let arrow = (k, v) => lengthReviver(k, v);
  for (var i = 0; i < 3; i++) {
    assertEquals('{"a":"undefined"}', stringify(parse('{"a":103}', arrow)));
    assertEquals(