AV *			T_AVREF

INPUT

T_AVREF
	if (SvROK($arg) && SvTYPE(SvRV($arg))==SVt_PVAV)
	    $var = (AV*)SvRV($arg);
	else
	    Perl_croak(aTHX_ \"$var is not an array reference\")

OUTPUT

T_AVREF
	$arg = newRV((SV*)$var);