RFR(XS): 8241695: JFR TestCrossProcessStreaming.java child process exited with SIGQUIT (131)

[mikhailo.seledtsov at oracle.com]

Please review this change that prevents SIGQUIT used by VM.attach from 
killing the child process. It is a work-around in a sense. Waiting for 
the child process to be fully initialized is generally a good idea 
before attempting to attach to it.

     JBS: https://bugs.openjdk.java.net/browse/JDK-8241695
     Webrev: http://cr.openjdk.java.net/~mseledtsov/8241695.00/
     Testing:
        Ran this test over 200 times: ALL PASS


Thank you,
Misha