[15] RFR(S): 8241803: JFR TestThreadStartEndEvents.java failed due to "RuntimeException: Wrong thread id"

[Markus Gronlund]

Greetings,

Please review the following changeset.

Bug: https://bugs.openjdk.java.net/browse/JDK-8241803 
Webrev: http://cr.openjdk.java.net/~mgronlun/8241803/webrev00/
Testing: jdk_jfr

Summary: 
The test assumes there is an ordering to the events. This is true for events of type Thread Start because of the coordination over latches as part of starting threads in the test, but it is not true for events of type Thread End. The order of events of type Thread End is non-deterministic, because the event is committed as part of dismantling the JavaThread in the VM, post Thread.isAlive() returning false.

Thanks
Markus