hg: jdk10/sandbox/hotspot: 8186095: upgrade to jtreg 4.2 b08

[chris.hegarty at oracle.com]

Changeset: a25c89a1b80a
Author:    iignatyev
Date:      2017-08-20 20:36 -0700
URL:       http://hg.openjdk.java.net/jdk10/sandbox/hotspot/rev/a25c89a1b80a

8186095: upgrade to jtreg 4.2 b08
Reviewed-by: rriggs, mchung, dholmes, iklam

! test/TEST.ROOT
! test/runtime/Metaspace/FragmentMetaspaceSimple.java