Repro: https://codesandbox.io/s/fast-water-4i4jb

Notice the flash. I'd expect `suspended` to be `true` during the high pri render.
Scheduler.unstable_advanceTime(1500);
    await advanceTimers(1500);
    expect(Scheduler).toFlushAndYield(['Suspend! [A]', 'Loading A...']);
    
    expect(ReactNoop.getChildren()).toEqual([]);
    
    Scheduler.unstable_runWithPriority(Scheduler.unstable_IdlePriority, () =>
      ReactNoop.render(<Foo renderContent={2} />),
    );
    
    expect(Scheduler).toFlushAndYield([]);
    
    expect(ReactNoop.getChildren()).toEqual([]);
    
    Scheduler.unstable_advanceTime(150);
    await advanceTimers(150);
    
    expect(ReactNoop.getChildren()).toEqual([]);
    
    Scheduler.unstable_advanceTime(600);
    await advanceTimers(600);
    expect(ReactNoop.getChildren()).toEqual([span('Loading A...')]);
  });
  describe('delays transitions when there a suspense config is supplied', () => {
    const SUSPENSE_CONFIG = {
      timeoutMs: 2000,
    };
    it('top level render', async () => {
      function App({page}) {