* extra SV*, used only during its construction and which is not used by
* regexec.c. Note that the 'next_off' field is unused, as the SSC stands
* alone, so there is never a next node. Also, there is no alignment issue,
* extra SV*, used only during its construction and which is not used by
* regexec.c. Note that the 'next_off' field is unused, as the SSC stands
* alone, so there is never a next node. Also, there is no alignment issue,