Review request: 8025096: Move the ChunkManager instances out of the VirtualSpaceLists

[Stefan Karlsson]

http://cr.openjdk.java.net/~stefank/8025096/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8025096

In the fix for 'JDK-8024547 
<https://bugs.openjdk.java.net/browse/JDK-8024547>: MaxMetaspaceSize 
should limit the committed memory used by the metaspaces' we need to 
make a clearer distinction between when new memory is committed and when 
memory is allocated inside already committed memory.

Moving the ChunkManager, which handles the free chunk list, out of the 
VirtualSpaceList, which handles the committed metaspace memory, is a 
step in that direction.

Changes:
- Move the ChunkManager instances from VirtualSpaceList to SpaceManager.
- Move the inc_container_count() into ChunkManager::free_chunks_get. Now 
the Chunk manager calls dec_container_count when chunks are inserted in 
the chunk free list and inc_container_count when chunks are removed from 
the chunk free list.
- Moved the ChunkManager::chunk_freelist_allocate() call out from the 
VirtualSpaceList::get_new_chunk()

thanks,
StefanK