RFR: JDK-8060017: Report heap sizing time

[Eric Caspole]

Hi,
Please review this fix for showing the details of heap expansion time in the PrintGCDetails.

https://bugs.openjdk.java.net/browse/JDK-8060017
http://cr.openjdk.java.net/~ecaspole/JDK-8060017/02/webrev/

The time to expand the heap is shown in the "Other" section at the end of each GC cycle info.

I tested this with a smallish app with a high allocation rate which does a lot of heap expands depending on the command line options used. Also, passes JPRT. The output shows up and graphs correctly in the gc log app.
Thanks,
Eric