RFR: 8200105: Remove cyclic dependency between oop.inline.hpp and collectedHeap.inline.hpp

[Stefan Karlsson]

Hi all,

Please review this patch to remove a cyclic dependency between 
oop.inline.hpp and collectedHeap.inline.hpp:

http://cr.openjdk.java.net/~stefank/8200105/webrev.01/
https://bugs.openjdk.java.net/browse/JDK-8200105

The ground work for this cleanup had already been done with:
8199728: Remove oopDesc::is_scavengable

What's done in this trivial patch is:
1) Move some debug functions out from the collectedHeap.inline.hpp and 
into collectedHeap.hpp.

2) Removed collectedHeap.inline.hpp and fixed missing includes to make 
it compile again.

Thanks,
StefanK