RFR: 8200169: Flatten G1Allocator class hierarchy

[Thomas Schatzl]

Hi,

On Fri, 2018-03-23 at 14:32 +0100, Stefan Johansson wrote:
> Hi,
> 
> Please review this change to remove some unnecessary class
> hierarchies 
> in G1.
> 
> Links
> JBS: https://bugs.openjdk.java.net/browse/JDK-8200169
> Webrev: http://cr.openjdk.java.net/~sjohanss/8200169/00/
> 
> Summary
> After the removal of several extension points and some other cleanups
> in G1, there is no longer any need for the two class hierarchies in 
> g1Allocator.hpp. These can be flattened to only consist of two
> concrete classes instead.

  looks good to me.

Thomas