- Use `NOTIFICATION_ENTER`/`EXIT_WORLD` for `Area` (intead of `*_TREE`).
- Now both bodies' and areas' constraints are cleaned up.
- And now also that happens as soon as the space is set to null (i.e., when exiting the tree) instead of only at freeing time.
- When clearing constraints, the loop goes on to the next if the current is already released, instead of breaking.
- When one has been already released, no error is shown from now on, as it's something expected, since a pair (our kind of constraint of interest) can be freed by any of its involved collision objects and the other will try again.
- Implement index shifting (or marking as -1) for shapes indices in collision pairs shapes are removed.
- Standarize behavior of bodies and areas so that anything that invalidates a given pair gives the same result (collision mask, actual collision, etc); for instance, triggering area enter/exit signals.
- Add missing member initializations.
- Extend the new-space-equals-area/body-current-space test to every case.
- Fix 3D ray-casts early accepting Areas (skipping the mask check).
- Fix unpairing of large elements (2D's `BroadPhase2DHashGrid`).
Some of these prevent random crashes caused by constraints with dangling pointers to involved objects.
Fixes#8856.
Fixes#7589.
Fixes#6676.
And maybe others.