dfa: prefer functions and constants to macros * lib/dfa.c: Prefer constants to macros where either will do. (streq, isasciidigit, newline_constraint) (letter_constraint, other_constraint, succeeds_in_context) (prev_newline_constraint, prev_letter_constraint) (prev_other_constraint, prev_newline_dependent) (prev_letter_dependent, accepting, accepts_in_context): Now static functions instead of function-like macros. Use lower-case names accordingly. All uses changed.