Repro case with a master build: https://codesandbox.io/s/stoic-mcnulty-dhygf?file=/src/App.js:668-703

Expected: we see content after a second.
Actual: fallback never resolves.

This happens in a sequence of:

1. Normal update
   - which suspends
2. Idle update
   - which also suspends
3. An unrelated normal update immediately followed by a ping (so they're batched)
   - here, we decide to stay on fallback, but should've shown the content

If you remove `_setVersion(v => v + 1);` on line 44 then the issue goes away.
setTextA('A1');
      
      startTransition(() => {
        
        
        
        
        setTextA('A2');
        setTextB('B2');
      });
      expect(Scheduler).toFlushAndYield([
        'B',
        'Suspend! [A1]',
        'Loading...',
        'Suspend! [A2]',
        'Loading...',
        'Suspend! [B2]',
        'Loading...',
      ]);
      expect(root).toMatchRenderedOutput(
        <>
          <span prop="A" />
          <span prop="B" />
        </>,
      );
      await resolveText('A1');
      expect(Scheduler).toHaveYielded(['Promise resolved [A1]']);
      expect(Scheduler).toFlushAndYield([
        'A1',