[14] 8236743: JFR: assert(klass != __null) failed: invariant in ObjectSampleCheckpoint::add_to_leakp_set

[Markus Gronlund]

Greetings,

Please help review the following change set:

Bug: https://bugs.openjdk.java.net/browse/JDK-8236743 
Webrev: http://cr.openjdk.java.net/~mgronlun/8236743/webrev01/
Tests : jdk_jfr
Summary: Please see the bug for a (lengthy) description of the problem and suggested solution.

Thanks
Markus