RFR(XS): 8239916 - SA: delete dead code in jdk.hotspot.agent/share/classes/sun/jvm/hotspot/oops/ObjectHeap.java

[臧琳]

Hi,
    Please review the following change:
    Bugs: https://bugs.openjdk.java.net/browse/JDK-8239916
    webrev: http://cr.openjdk.java.net/~lzang/8239916/webrev/

Thanks,
Lin