hg: shenandoah/jdk10/hotspot: Uses keep_alive_barrier to keep deduped char array alive

[zgu at redhat.com]

Changeset: 0776e379c034
Author:    zgu
Date:      2017-10-11 16:07 -0400
URL:       http://hg.openjdk.java.net/shenandoah/jdk10/hotspot/rev/0776e379c034

Uses keep_alive_barrier to keep deduped char array alive

! src/share/vm/gc/g1/g1StringDedupTable.cpp