damon_next_region
r = damon_next_region(r);
next = damon_next_region(r);
damon_insert_region(new, r, damon_next_region(r), t);
r2 = damon_next_region(r);
r2 = damon_next_region(r);
r_new = damon_next_region(r);
next = damon_next_region(r);