This change makes jstat output '-' instead of '\ufffd' when the result of a calculation is NaN. '\ufffd' is typically not displayable in a terminal.
This change also updates the tests to allow '-' as the output int the CCS (Compressed Class Space Space - Percent Used) column from -gcutil and -gccause. It can be hard to see from the diff but what I have done is change the regexp for that column from: [0-9]+\.[0-9]+ to: ([0-9]+\.[0-9]+)|- Testing: Passes tests locally, currently running JPRT. webrev: http://cr.openjdk.java.net/~sla/8025427/webrev.00/ bug: https://bugs.openjdk.java.net/browse/JDK-8025427 Thanks, /Staffan
