I’d say RFC 0004: HEAP escape analysis for starters?
Now, about Automatic Reference Counting (ARC) you’re making me curious 
But I’d see ARC as an alternative to the GC (or something like Immix RC), not happening as a parallel HEAP to the GC HEAP. For example the GC would still have to scan & mark the ARC HEAP and do pauses for collections Saw your previous message 
