hg: shenandoah/jdk: Avoid write barrier during full GC

[zgu at redhat.com]

Changeset: 3bac6b3985c8
Author:    zgu
Date:      2018-10-31 20:02 -0400
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/3bac6b3985c8

Avoid write barrier during full GC

! src/hotspot/share/gc/shenandoah/shenandoahBarrierSet.cpp