RFR (S): 8136398: Create test that checks that G1 MixedGC produces correct output to logfile

[Kirill Zhaldybin]

Hi!

Could you please review a patch for JDK-8136398?

I added very simple test that starts JVM  with "-XX:+PrintGC" or 
"-XX:+PrintGCDetails" flags, provokes mixed gc and checks that 
corresponding log entry appears in gc log.

CR: https://bugs.openjdk.java.net/browse/JDK-8136398

Webrev:

hotspot: http://cr.openjdk.java.net/~kzhaldyb/webrevs/JDK-8136398/webrev.00/

Thank you.

Regards, Kirill