ppath_push
ppath_t *ppath_push(ppath_t *, ppath_component_t *);
ppath_push(np, pc);
p = ppath_push(p0, pc);
p = ppath_push(p0, pc);
rp = ppath_push(p, pc);
rp = ppath_push(p, pc);
rp = ppath_push(p, pc);
rp = ppath_push(p, pc);
rp = ppath_push(p, pc);
rp = ppath_push(p, pc);
rp = ppath_push(p, pc);
rp = ppath_push(p, pc);