RFR(S): 8198337: -XX:StartFlightRecording=dumponexit=true, disk=false doesn't work

[Erik Gahlin]

Hi,

Could I please have a review of this fix.

Problem is that a recording file is not written when the JVM exits, if 
the user starts it up with 
-XX:StartFlightRecording:dumponexit=true,disk=false.

This is because data is dumped directly from memory to file, bypassing 
the disk repository, which means the generated filename is not used. If 
the user specify a filename, or disk=true (which is default), this 
doesn't happen.

Bug:
https://bugs.openjdk.java.net/browse/JDK-8198337

Webrev:
http://cr.openjdk.java.net/~egahlin/8198337.1/

Testing:
Added a test case and ran existing tests in test/jdk/jdk/jfr.

Will fix typo before checking in ("recoding" -> "recording")

Thanks
Erik