hg: shenandoah/jdk10: Enable biased locking for Shenandoah by default

[ashipile at redhat.com]

Changeset: 9a3eab130621
Author:    shade
Date:      2017-11-20 14:05 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk10/rev/9a3eab130621

Enable biased locking for Shenandoah by default

! src/hotspot/share/runtime/arguments.cpp