RFR (S): 8252034: G1: Remove *g1_reserved* methods

[Kim Barrett]

> On Aug 19, 2020, at 4:51 PM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
> 
> Hi all,
> 
>  can I have reviews for this change that removes the G1CollectedHeap::*g1_reserved* methods?
> 
> They duplicate existing functionality actually just right below them.
> 
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8252034
> Webrev:
> http://cr.openjdk.java.net/~tschatzl/8252034/webrev/
> Testing:
> tier1
> 
> Thanks,
>  Thomas

I dislike that we still have two places (CollectedHeap::_reserved and
HeapRegionManager) that have the reserved region information, and it seems
hard to *prove* they are the same, even though they must be.

But okay, looks good.