RFR: 8138888: Remove ExtendedOopClosure::apply_to_weak_ref_discovered_field

[Thomas Schatzl]

Hi Stefan,

On Tue, 2017-04-25 at 13:41 +0200, Stefan Johansson wrote:
> Hi,
> 
> Please review this change for:
> https://bugs.openjdk.java.net/browse/JDK-8138888
> 
> Webrev:
> http://cr.openjdk.java.net/~sjohanss/8138888/hotspot.00/
> 
> Summary:
> This change builds upon 8138737 which is currently out for review.
> With that change we now have a more generic mechanism to add special
> handling for closures when visiting InstanceRefKlasses. With this
> mechanism we can remove
> ExtendedOopClosure::apply_to_weak_ref_discovered_field and 
> replace it with a new ReferenceIterationMode which provides the same 
> functionality.
> 
> The RFE in JBS also proposes to remove the functionality of
> apply_to_weak_ref_discovered_field, but to do this some more analysis
> is needed. Doing this changes is a step in the direction of making it
> easier to remove the need for this functionality in future changes.
> 

  looks good.

Thomas