fr_fastroute
(void) fr_fastroute(m, mp, fin, NULL);
(void) fr_fastroute(m, mp, fin, fdp);
(void) fr_fastroute(mc, &mc, fin, &fr->fr_dif);
i = fr_fastroute(m, mpp, &fnew, NULL);
extern int fr_fastroute __P((mb_t *, mb_t **, fr_info_t *, frdest_t *));