Revisit aggressive code cache sweeping behaviour

Running a big IDE I have noticed the code cache being close to full. The aggressive sweeping is triggered by the non-profiled code-heap being 90% full, but there is still a lot of room in the profiled-heap.

Non-profiled code can be allocated in the profiled-heap. Aggressive sweeping shouldn't be triggered before the combined space is starting to run out.

Changing this allows for more effective use of codecache space.