OP_BACKREF1      1684 ext/mbstring/oniguruma/regcomp.c 	  case 1:  r = add_opcode(reg, OP_BACKREF1); break;
OP_BACKREF1      5716 ext/mbstring/oniguruma/regcomp.c   { OP_BACKREF1,            "backref1",             ARG_NON },
OP_BACKREF1      2127 ext/mbstring/oniguruma/regexec.c     case OP_BACKREF1:  MOP_IN(OP_BACKREF1);