RFR: Add remaining unused free space to 'used' counter in free list

[Zhengyu Gu]

Look good.

-Zhengyu


On 12/13/2016 12:03 PM, Roman Kennke wrote:
> I noticed that when a program allocates many objects that are slightly
> larger than half a region, we would continuously run into full GC. The
> reason is that when we skip to next region for allocation, we did not
> count the remaining unused free space as 'used', and thus barely
> reported half of heap remaining when running OOM. Oops.
>
> Fixed in ShenandoahFreeList by adding last-current-region's remaining
> free() to the free-lists used.
>
> Ok?
>
> http://cr.openjdk.java.net/~rkennke/fixused/webrev.00/
>
> Roman