Function pop

docs/external/js/react-dom.development.js:10759–10782

(cursor, fiber)

  }

  function pop(cursor, fiber) {
    if (index < 0) {
      {
        error('Unexpected pop.');
      }

      return;
    }

    {
      if (fiber !== fiberStack[index]) {
        error('Unexpected Fiber popped.');
      }
    }

    cursor.current = valueStack[index];
    valueStack[index] = null;

    {
      fiberStack[index] = null;
    }

    index--;
  }

  function push(cursor, value, fiber) {
    index++;