ONIGENC_CASE_FOLD_DEFAULT  847 re.c               r = onig_reg_init(*reg, option, ONIGENC_CASE_FOLD_DEFAULT, enc, syntax);
ONIGENC_CASE_FOLD_DEFAULT 5969 regcomp.c        r = onig_reg_init(reg, option, ONIGENC_CASE_FOLD_DEFAULT, enc, syntax);
ONIGENC_CASE_FOLD_DEFAULT 5986 regcomp.c        r = onig_reg_init(*reg, option, ONIGENC_CASE_FOLD_DEFAULT, enc, syntax);