http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2016-May/019311.html
http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2016-May/019380.html

LogFileOutput for UL uses fopen(3) to open logfile.
However, it might not handle > 2GB size file.

  http://man7.org/linux/man-pages/man2/open.2.html

Actually, JDK-7122222 added _FILE_OFFSET_BITS macro for GC log.
I guess we need this macro for UL.