Sandbox: https://codesandbox.io/s/cranky-kapitsa-op3jh

Repro: type "a" and then after a second "b"

Expected: Eventually you'll see "ab" in all fields. Pending "..." indicator goes away.

Actual: You'll keep seeing "a" in low pri field. Pending "..." indicator is stuck.
Scheduler.unstable_yieldValue('Parent');
          const updaterRef = React.useRef(null);
          React.useEffect(() => {
            Scheduler.unstable_yieldValue('Parent passive create');
            return () => {
              updaterRef.current(true);
              Scheduler.unstable_yieldValue('Parent passive destroy');
            };
          }, []);
          return <Child updaterRef={updaterRef} />;
        }
        function Child({updaterRef}) {