no-pointer areas

[Craig Black]

> Huh? Isn't it so that calls to malloc/calloc are already not scanned by 
> the GC (besides also not being GC managed), and only when 
> addRoots/addRange is used on such segments are they scanned by the GC?

You are right.  This is still a good idea.  addRoot and addRange could have 
an additional parameter that would indicate if the allocation unit contains 
pointers or not.

-Craig