Consistently use C99 flexible arrays and bounds checking
This is an issue to track some work which I’ve mostly completed, but which needs to wait until GLib 2.82, so I don’t have a full MR ready yet.
WIP branch is: https://gitlab.gnome.org/GNOME/glib/-/commits/wip/pwithnall/fsanitize-bounds
It basically implements https://people.kernel.org/kees/bounded-flexible-arrays-in-c for GLib