With the exception of gtk_buildable_get_id(), those are only used
to construct objects from XML descriptions, which is functionality
internal to GTK.
The API is therefore unlikely to be missed, and keeping it internal
means they can no longer unintentionally shadow object methods in
bindings with less namespacing; for example it's currently ambiguous
whether `infoBar.add_child()` refers to gtk_info_bar_add_child() or
gtk_buildable_add_child().
https://gitlab.gnome.org/GNOME/gtk/-/issues/3191
Change the format of GtkBuilder <menu> to be more in-line with the style
of the rest of GtkBuilder so that we can do translation in a consistent
way.
The format is now substantially more difficult to hand-write, but tools
should be along soon.
There is an xslt program attached to the bug to help you convert your
existing .ui files from the old format to the new one.
https://bugzilla.gnome.org/show_bug.cgi?id=668696