RFR (S): 8191567: Refactor ciInstanceKlass G1 keep alive barrier to use Access API.

[Roman Kennke]

Am 24.11.2017 um 17:22 schrieb Erik Österlund:
> Hi,
> 
> When creating a ciInstanceKlass handle, G1 might need a SATB barrier to 
> keep "peeked" weak klass pointers alive during marking.
> This should now be done with the Access API instead of manual calls to 
> the G1 SATB barrier.
> 
> Bug:
> https://bugs.openjdk.java.net/browse/JDK-8191567
> 
> Webrev:
> http://cr.openjdk.java.net/~eosterlund/8191567/webrev.00/
> 
> Thanks,
> /Erik

Looks good.

There are many more places where G1SATBCardTableModRefBS::enqueue() is 
callled from shared code that would require the same treatment. Are you 
planning to take them one by one? Otherwise, maybe squeeze them all into 
this patch too because it's related and similar?

Roman