GLib is used a subproject with GObject Introspection and overriding
this binary breaks that usage. For now we will make overriding the
binary conditional until Meson is updated to handle the binary changes.
Since `GITypelib` is exposed in the public libgirepository API, it needs
to be a boxed type. So we either need to add a `copy` method to mirror
the existing `free` method, or switch to refcounting. The latter option
seems better, since a `GITypelib` contains internal state about open
`GModule`s and the semantics for copying that would be potentially
complex.
Signed-off-by: Philip Withnall <pwithnall@gnome.org>
Helps: #3155
Adapt gi-compile-repository sources to compile against the updated
libgirepository that is included with GLib.
This also renames "g-ir-compiler" to "gi-compile-repository" to avoid
overwriting the existing binary and to simplify the binary name going
forward.