RFR 8215699: -Xlog::file cannot be used with named pipe

[Harold David Seigel]

Hi,

Please review this fix for JDK-8215699.  The fix sets the default 
logging file count to zero if the log file is a named pipe.  This 
prevents the logging code from complaining about trying to do log file 
rotation with a non-regular file.

Open Webrev: 
http://cr.openjdk.java.net/~hseigel/bug_8215699/webrev/index.html

JBS Bug:  https://bugs.openjdk.java.net/browse/JDK-8215699

The fix was tested by hand on both Linux-x64 and Mac OS X. Logging to a 
named pipe worked when no filecount was specified and when filecount=0 
was specified.

The fix was regression tested by running Mach5 tiers 1 and 2 tests and 
builds on Linux-x64, Windows, and Mac OS X, Mach5 tiers 3 -5 on 
Linux-x64, and by running JCK-12 Lang and VM tests on Linux-x64.

Thanks, Harold