Add OS X compatibility functions
It would be great if we could have some compatibility functions for OS X, akin to those for win32 (https://developer.gnome.org/glib/unstable/glib-Windows-Compatibility-Functions.html). In particular, it would be great to be able to obtain the bundle path if available. We currently do our own patches  , but it would make sense I think to include this into glib, together with G_OS_OSX (or something similar).
 https://git.gnome.org/browse/libpeas/tree/libpeas/peas-dirs.c?id=3403cbe36922517be8e19fdf506274d54d29fd92#n33  https://git.gnome.org/browse/gtksourceview/tree/gtksourceview/gtksourceview-i18n.c?id=4bf401661a4ca1b204a62bddfc99aacb56f429ce#n35