RFR: Implementation of JEP 387: Elastic Metaspace (round two)

[Leo Korinth]

Hi!

I have a question regarding ChunkManager::purge().

In part: 1) purge virtual space list

We try to purge empty VirtualSpaceNodes. We also remove the free chunks
from the free list (_chunks) if we are successful. I can not see that
we ever uncommit these chunks.

Later, in part: 2) uncommit free chunks

We iterate the free list and uncommits the free chunks, the problem is
that we might have removed chunks from the free list in part 1 even though
we did no uncommit.

To me, it seems we are missing to uncommit memory here, I am probably missing something, but what?

Thanks,
Leo