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('Component');
          const [didLoad, setDidLoad] = React.useState(false);
          React.useLayoutEffect(() => {
            Scheduler.unstable_yieldValue('layout create');
            
            completePendingRequest = () => setDidLoad(true);
            return () => {
              Scheduler.unstable_yieldValue('layout destroy');
            };
          }, []);
          return didLoad;
        }
        act(() => {
          ReactNoop.renderToRootWithID(<Component />, 'root', () =>
            Scheduler.unstable_yieldValue('Sync effect'),
          );
          expect(Scheduler).toFlushAndYieldThrough([
            'Component',
            'layout create',