RFR(S): 8229209: [TESTBUG] test for cross-process JFR event streaming

[Mikhailo Seledtsov]

Please review this new JFR test. In this test the producer of JFR events 
and the consumer run in separate processes.
This is expected to be a common scenario with JFR streaming for 
monitoring applications and services.

     JBS: https://bugs.openjdk.java.net/browse/JDK-8229209
     Webrev: http://cr.openjdk.java.net/~mseledtsov/8229209.01/
     Testing:
       - ran this new test locally (Mac, Linux-x64) multiple times - PASS
       - running this test on the test cluster - in progress


Thank you,
Misha