[Matrix]: expose sub vector in local_vec_store.
[Matrix]: expose sub vector in local_vec_store.

Conflicts:
	matrix/local_vec_store.h

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