[Gc] Combining collected and uncollected heaps

[Hans Aberg]

There is the general problem of combining collected and uncollected heaps.

Objects can be collected and uncollected. Further, pointers can be traced and untraced.

The objects on the heap that is not collected by the GC should initially be marked uncollected. Only pointers to the GC heap should be traced.

When an object expires on the uncollected heap, it should be marked for for collection by the GC. It will then stay alive until the GC finds it is dead.

Hans