The reason why we were checking lexer state in addition to token was
that we do not want to colorize local variable, method call, etc., while
they share the :on_ident token with a name of method definition which
should be colored as blue.
It means that we're concerned about the lexer state only for :on_ident.
Thus we can skip checking lexer state for non-:on_ident tokens. This
refactoring is based on that idea.
Also, now we manage Ripper's lexer state as Integer (use `|` if you
need to check multiple states). It should be faster than using Array of
Integer because #any? block call is not needed.