Darwin Heap Enumerator

[RobertNotRob]

Hey FZ,

I noticed your Darwin "is_heap" implementation filtered based on !is_stack && !is_code.

I've worked up a implementation which enumerates the zones using XNU's malloc introspection APIs. This will hopefully give more performant and accurate analysis.

I need to verify this does in fact give all heap regions as some valid pointers (such as where heap zones metadata) are not found, which is somewhat suspicious. However, I thought it best to open this up for you guys to review asap.

Thanks, Robert