hg: jdk/sandbox: 8192897: NPE occurs on clhsdb jstack

[chris.hegarty at oracle.com]

Changeset: e9ad230ea455
Author:    ysuenaga
Date:      2017-12-04 10:23 +0900
URL:       http://hg.openjdk.java.net/jdk/sandbox/rev/e9ad230ea455

8192897: NPE occurs on clhsdb jstack
Reviewed-by: dholmes, sspitsyn, jgeorge, sballal

! src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/CompiledVFrame.java
! test/hotspot/jtreg/serviceability/sa/ClhsdbJstack.java