RFR: 8198511: Move allocation functions from GenCollectorPolicy to GenCollectedHeap

[Stefan Karlsson]

Hi all,

Please review this patch that moves the allocation functions out from 
GenCollectorPolicy into GenCollectedHeap.

  http://cr.openjdk.java.net/~stefank/8198511/webrev.01/
  https://bugs.openjdk.java.net/browse/JDK-8198511

The patch simply moves the function to GenCollectedHeap, removes a bunch 
of gch-> indirections that are not needed anymore, and adds a small 
number of gen_policy()-> indirections.

The patch is a step towards:
  https://bugs.openjdk.java.net/browse/JDK-8198505

Thanks,
StefanK