* src/tgbaalgos/scc.hh (scc_map::scc): Add a supp_rec member to
hold reachable APs.
* src/tgbaalgos/scc.cc (scc_map::update_supp_rec): New function,
to update supp_rec.
(scc_map::build_map): Call it.
(scc_map::aprec_set_of): New function.
(dump_scc_dot): Show the output of aprec_set_of().