Revert "stop T_IN/OUT/INOUT/STDIO typemaps leaking"

This reverts commit 50e5165.

That commit fixed the leak too well and instead introduced a potential
premature free.

This re-introduces the long-standing leak, which will be addressed post
5.22 release.

See RT #124181

lib/ExtUtils/typemap

@@ -388,48 +388,32 @@ T_STDIO
 	{
 	    GV *gv = newGVgen("$Package");
 	    PerlIO *fp = PerlIO_importFILE($var,0);
-	    if ( fp && do_open(gv, "+<&", 3, FALSE, 0, 0, fp) ) {
-                SV *rv = newRV_noinc((SV*)gv);
-                rv = sv_bless(rv, gv_stashpv("$Package",1));
-		sv_setsv($arg, rv);
-                SvREFCNT_dec_NN(rv);
-            }
+	    if ( fp && do_open(gv, "+<&", 3, FALSE, 0, 0, fp) )
+		sv_setsv($arg, sv_bless(newRV((SV*)gv), gv_stashpv("$Package",1)));
 	    else
 		$arg = &PL_sv_undef;
 	}
 T_IN
 	{
 	    GV *gv = newGVgen("$Package");
-	    if ( do_open(gv, "<&", 2, FALSE, 0, 0, $var) ) {
-                SV *rv = newRV_noinc((SV*)gv);
-                rv = sv_bless(rv, gv_stashpv("$Package",1));
-		sv_setsv($arg, rv);
-                SvREFCNT_dec_NN(rv);
-            }
+	    if ( do_open(gv, "<&", 2, FALSE, 0, 0, $var) )
+		sv_setsv($arg, sv_bless(newRV((SV*)gv), gv_stashpv("$Package",1)));
 	    else
 		$arg = &PL_sv_undef;
 	}
 T_INOUT
 	{
 	    GV *gv = newGVgen("$Package");
-	    if ( do_open(gv, "+<&", 3, FALSE, 0, 0, $var) ) {
-                SV *rv = newRV_noinc((SV*)gv);
-                rv = sv_bless(rv, gv_stashpv("$Package",1));
-		sv_setsv($arg, rv);
-                SvREFCNT_dec_NN(rv);
-            }
+	    if ( do_open(gv, "+<&", 3, FALSE, 0, 0, $var) )
+		sv_setsv($arg, sv_bless(newRV((SV*)gv), gv_stashpv("$Package",1)));
 	    else
 		$arg = &PL_sv_undef;
 	}
 T_OUT
 	{
 	    GV *gv = newGVgen("$Package");
-	    if ( do_open(gv, "+>&", 3, FALSE, 0, 0, $var) ) {
-                SV *rv = newRV_noinc((SV*)gv);
-                rv = sv_bless(rv, gv_stashpv("$Package",1));
-		sv_setsv($arg, rv);
-                SvREFCNT_dec_NN(rv);
-            }
+	    if ( do_open(gv, "+>&", 3, FALSE, 0, 0, $var) )
+		sv_setsv($arg, sv_bless(newRV((SV*)gv), gv_stashpv("$Package",1)));
 	    else
 		$arg = &PL_sv_undef;
 	}