RFR: Refactor ShenandoahFreeSet

[Roman Kennke]

Am 04.09.2017 um 17:28 schrieb Aleksey Shipilev:
> http://cr.openjdk.java.net/~shade/shenandoah/refactor-freeset/webrev.01/
> 
> Several improvements:
>  a) Untangle from ShenandoahHeapRegionSet, in anticipation for merging with cset and other
> facilities for centralized region handling;
>  b) Rewrite humongous allocation path with a simpler code;
>  c) Simplify unsafe_peek_free;
>  d) Various style improvements;
> 
> Testing: hotspot_gc_shenandoah
> 
> Thanks,
> -Aleksey
> 

Looks good!

Roman