hg: shenandoah/jdk9/hotspot: Enable fast synchronizer root scanning by default

[ashipile at redhat.com]

Changeset: 63015cf54987
Author:    shade
Date:      2017-05-11 11:24 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk9/hotspot/rev/63015cf54987

Enable fast synchronizer root scanning by default

! src/share/vm/gc/shenandoah/shenandoah_globals.hpp