Revert "[Graph]: remove array_index_iterator_impl."
Revert "[Graph]: remove array_index_iterator_impl."

This reverts commit 4e2b97d2012812af75c49c5939bdd78b7667e481.

zheng-da/FlashX,icoming/FlashX,flashxio/FlashX,flashxio/FlashX,icoming/FlashX,silky/FlashGraph,icoming/FlashX,icoming/FlashGraph,zheng-da/FlashX,flashxio/FlashX,zheng-da/FlashX,icoming/FlashX,icoming/FlashGraph,zheng-da/FlashX,flashxio/FlashX,zheng-da/FlashX,silky/FlashGraph,icoming/FlashGraph,silky/FlashGraph,icoming/FlashGraph,icoming/FlashGraph,silky/FlashGraph,flashxio/FlashX,silky/FlashGraph,icoming/FlashX,flashxio/FlashX