gio: add support for g_auto() and g_autoptr()

Add support to libgio types for the new cleanup macros.

https://bugzilla.gnome.org/show_bug.cgi?id=743640

gio/gwin32outputstream.h

@@ -42,6 +42,8 @@ typedef struct _GWin32OutputStream         GWin32OutputStream;
 typedef struct _GWin32OutputStreamClass    GWin32OutputStreamClass;
 typedef struct _GWin32OutputStreamPrivate  GWin32OutputStreamPrivate;
 
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(GWin32OutputStream, g_object_unref)
+
 struct _GWin32OutputStream
 {
   GOutputStream parent_instance;