RFR 8205610: [TESTLIB] Improve listing of open file descriptors

[Roger Riggs]

Please review a suggested improvement to the test library that lists 
open file descriptors,
adding support for Solaris pfiles.

webrev:
    http://cr.openjdk.java.net/~rriggs/webrev-lsof-8205610/
Issue:
    https://bugs.openjdk.java.net/browse/JDK-8205610

Thanks, Roger