scan_limit        296 gc/finalize.c      ptr_t scan_limit;
scan_limit        300 gc/finalize.c         scan_limit = p + descr - sizeof(word);
scan_limit        302 gc/finalize.c         scan_limit = target_limit + 1 - sizeof(word);
scan_limit        304 gc/finalize.c      for (q = p; q <= scan_limit; q += ALIGNMENT) {