nitcc: minimize DFA

Signed-off-by: Jean Privat <jean@pryen.org>
nitcc: uptate tests wrt DFA minimization

Signed-off-by: Jean Privat <jean@pryen.org>
nitcc: add Automaton::reverse

Signed-off-by: Jean Privat <jean@pryen.org>
nitcc: add tests/lexer-aaa

Signed-off-by: Jean Privat <jean@pryen.org>