REG_EESCAPE_IDX   152 maint/gnulib/lib/regcomp.c #define REG_ESUBREG_IDX	(REG_EESCAPE_IDX + sizeof "Trailing backslash")
REG_EESCAPE_IDX   193 maint/gnulib/lib/regcomp.c     REG_EESCAPE_IDX,