See rt.perl.org #117941 for the obscure problems that this lack of reference
counting can cause.
check_new_and_strlen(st, basecop->cop_file);
check_new_and_strlen(st, basecop->cop_stashpv);
#else
- sv_size(aTHX_ st, (SV *)basecop->cop_stash, SOME_RECURSION);
sv_size(aTHX_ st, (SV *)basecop->cop_filegv, SOME_RECURSION);
#endif