(save_column): sp, sp1, and sp2 are state_number_t.
(prepare): Rename `final' as `final_state_number', `nnts' as
`nterms_number', `nrules' as `rules_number', `nstates' as
`states_number', and `ntokens' as `tokens_number'. Remove `nsym',
unused.
* data/yacc.c, data/glr.c, data/lalr1.cc: Adjust.
* data/lalr1.cc (nsym_): Remove, unused.