hg: shenandoah/jdk: Disable evac assist by default until bugfixes arrive

[shade at redhat.com]

Changeset: d7237ab3d84d
Author:    shade
Date:      2018-08-23 19:11 +0200
URL:       http://hg.openjdk.java.net/shenandoah/jdk/rev/d7237ab3d84d

Disable evac assist by default until bugfixes arrive

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