hammer2_chain_repparent
hammer2_chain_t *hammer2_chain_repparent(hammer2_chain_t **chainp, int flags);
parent = hammer2_chain_repparent(parentp, how_maybe);
parent = hammer2_chain_repparent(parentp, how_maybe);
parent = hammer2_chain_repparent(parentp, how_maybe);
hammer2_chain_t *hammer2_chain_repparent(hammer2_chain_t **chainp, int flags);
parent = hammer2_chain_repparent(parentp, how_maybe);
parent = hammer2_chain_repparent(parentp, how_maybe);
parent = hammer2_chain_repparent(parentp, how_maybe);