With SVN 492, pcre2_get_error_message(100, ...) returns 8 for the length
of "no error". Before it returned 0 for an empty string. As far as I can
see, "no error" was never returned.
Since the check-in comment merely talks about compiler warnings, I do
not know if this regression is intended. It makes sense somewhat, but
might also break existing code which checks the error message instead of
the error code.
