roff_head_alloc
head = roff_head_alloc(man, line, ppos, tok);
n = roff_head_alloc(man, line, ppos, tok);
head = roff_head_alloc(mdoc, line, ppos, tok);
head = roff_head_alloc(mdoc, line, ppos, tok);
head = roff_head_alloc(mdoc, line, ppos, tok);
rew_last(mdoc, roff_head_alloc(mdoc, line, ppos, tok));
head = roff_head_alloc(mdoc, line, ppos, tok);
rew_last(mdoc, roff_head_alloc(mdoc, line, ppos, tok));
roff_head_alloc(mdoc, nchild->line, nchild->pos, MDOC_It);
struct roff_node *roff_head_alloc(struct roff_man *, int, int, int);