RFR 9: 8081567 : java/lang/ProcessHandle/InfoTest.java failed Cannot run program "whoami"

[Roger Riggs]

Please review a change to report the user/owner in ProcessHandle.info to
have the same form for the owner identification as provided by 
java.nio.Files.
On Windows it includes the domain with the user name.

The test is updated to remove a dependency on the OS command whoami
and instead compare the users process with the owner of a file created
by the process improving portability.

Webrev:
     http://cr.openjdk.java.net/~rriggs/webrev-whoami-8081567/

Issue:
   https://bugs.openjdk.java.net/browse/JDK-8081567

Thanks, Roger