The introspection scanner chokes fairly badly on the types we create,
and that got even worse when the autolist support landed. Now, every
time we declare a new GObject type we automatically get incomplete
aliases to container types that gobject-introspection and Vala do not
know how to handle.

Since the autoptr machinery is not really introspectable to begin with,
as it's a C utility extension that depends on the C compiler being used
to compile a C project that depends on GLib, we can mark the whole
section as non-introspectable using the __GI_SCANNER__ pre-processor
symbol.

https://bugzilla.gnome.org/show_bug.cgi?id=791342