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.
useEffect(() => {
          Scheduler.unstable_yieldValue(`Did create [${props.count}]`);
          return () => {
            Scheduler.unstable_yieldValue(`Did destroy [${props.count}]`);
          };
        });
        return <Text text={'Count: ' + props.count} />;
      }
      act(() => {
        ReactNoop.render(<Counter count={0} />, () =>
          Scheduler.unstable_yieldValue('Sync effect'),
        );
        expect(Scheduler).toFlushAndYieldThrough(['Count: 0', 'Sync effect']);
        expect(ReactNoop.getChildren()).toEqual([span('Count: 0')]);
      });
      expect(Scheduler).toHaveYielded(['Did create [0]']);
      act(() => {
        ReactNoop.render(<Counter count={1} />, () =>
          Scheduler.unstable_yieldValue('Sync effect'),
        );
        expect(Scheduler).toFlushAndYieldThrough(['Count: 1', 'Sync effect']);
        expect(ReactNoop.getChildren()).toEqual([span('Count: 1')]);
      });
      expect(Scheduler).toHaveYielded(['Did destroy [0]', 'Did create [1]']);
    });
    it('unmounts on deletion', () => {
      function Counter(props) {