Increases the reference counter for the return value. */
SV *perl_func_sv_inc(SV *func, const char *package);
-/* For compatibility with perl 5.004 and older */
-#ifndef HAVE_PL_PERL
-# define PL_sv_undef sv_undef
-extern STRLEN PL_na;
-#endif
-
#ifndef pTHX_
# define pTHX_
#endif