hg: jdk/sandbox: 8215985: ZGC: Simplify reference processing in light of JDK-8175797

[chris.hegarty at oracle.com]

Changeset: 03efcf7fc34b
Author:    kbarrett
Date:      2019-01-07 15:20 -0500
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/03efcf7fc34b

8215985: ZGC: Simplify reference processing in light of JDK-8175797
Summary: Only self-loop 'next' field for FinalReference deactivation.
Reviewed-by: eosterlund, pliden

! src/hotspot/share/gc/z/zReferenceProcessor.cpp
! src/hotspot/share/gc/z/zReferenceProcessor.hpp