hg: shenandoah/jdk10: Temporarily disable String deduplication

[ashipile at redhat.com]

Changeset: 18bada116c5f
Author:    shade
Date:      2017-11-17 18:28 +0100
URL:       http://hg.openjdk.java.net/shenandoah/jdk10/rev/18bada116c5f

Temporarily disable String deduplication

! src/hotspot/share/runtime/arguments.cpp
! test/hotspot/jtreg/gc/shenandoah/ShenandoahStrDedupStress.java
! test/hotspot/jtreg/gc/shenandoah/TestShenandoahStrDedup.java