>> Nevertheless, I factored the individual remove as
>> #primRemoveFromSystem:, just for you.  :)  So if some external caller
>> wants to use that they can (although doing it seems it leaves the
>> system in a bad state, maybe there's some use case I'm missing).
>
> All this environments and shrinking work I've been doing lately has made me
> aware of just how complicated and delicate class removal really is. I've
> been thinking we should do some work on simplifying it in 4.6.

One thing that's true is, I have no experience with shrinking, so,
that's fine.  There's no hurry on this.  :)

> It may be that this *should* be the default behaviour, but I'm with Tobias,
> we shouldn't change it lightly. If you want to release 4.5 soon, I don't
> think there's enough time to test a change this fundamental.

However, I do think that the image is basically nowhere in terms of
deleting classes.  IOW, no one ever deletes classes with subclasses
except during development.

> Also, a nit: since it's not really a primitive, #primRemoveFromSystem:
> should be called #basicRemoveFromSystem:

Sure, that's fine.  I just wanted it to be something that connotates
being at a "lower-level" than the API.  #basic does that just fine.