8240754: Instrument FlowTest.java to provide more debug traces.

[Daniel Fuchs]

Hi,

Please find below a changeset that adds some more debugging
output to FlowTest.java for better test failure diagnosis.

8240754: Instrument FlowTest.java to provide more debug traces.
https://bugs.openjdk.java.net/browse/JDK-8240754

webrev:
http://cr.openjdk.java.net/~dfuchs/webrev_8240754/webrev.00/

best regards,

-- daniel