girepository: Add g_autoptr() and g_auto() support

This should make the code a bit more usable in situations where people
aren’t potentially using MSVC.

Signed-off-by: Philip Withnall <pwithnall@gnome.org>

Helps: #3255

girepository/meson.build

@@ -56,6 +56,7 @@ girepo_headers = files(
   'gipropertyinfo.h',
   'giregisteredtypeinfo.h',
   'girepository.h',
+  'girepository-autocleanups.h',
   'gisignalinfo.h',
   'gistructinfo.h',
   'gitypeinfo.h',