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.
case 'forward':
          case 'backward': {
            console.error(
              '"%s" is not a valid value for revealOrder on <SuspenseList />. ' +
                'React uses the -s suffix in the spelling. Use "%ss" instead.',
              revealOrder,
              revealOrder.toLowerCase(),
            );
            break;
          }
          default:
            console.error(
              '"%s" is not a supported revealOrder on <SuspenseList />. ' +
                'Did you mean "together", "forwards" or "backwards"?',
              revealOrder,
            );
            break;
        }
      } else {
        console.error(
          '%s is not a supported value for revealOrder on <SuspenseList />. ' +
            'Did you mean "together", "forwards" or "backwards"?',
          revealOrder,
        );
      }
    }
  }
}
function validateTailOptions(
  Mode: SuspenseListTailMode,