OP_NULL_CHECK_START  344 mbstring/oniguruma/regcomp.c     r = add_opcode(reg, OP_NULL_CHECK_START);
OP_NULL_CHECK_START 5538 mbstring/oniguruma/regcomp.c   { OP_NULL_CHECK_START,    "null-check-start",     ARG_MEMNUM  },
OP_NULL_CHECK_START 2506 mbstring/oniguruma/regexec.c     case OP_NULL_CHECK_START:  STAT_OP_IN(OP_NULL_CHECK_START);