RFR: 8009032 - Implement evacuation info event

[Jesper Wilhelmsson]

Hi,

I'm looking for a couple of reviews for this change.

This is an tracing event with information about G1 evacuation/compaction. It 
contains the number of regions in from-space and to-space, how much data that 
was used before and after, the number of bytes copied during the 
evacuation/compaction, and how many regions that was completely freed during an 
evacuation.

Webrev: http://cr.openjdk.java.net/~jwilhelm/8009032/webrev/


The patch also contains a bunch of fixed typos in various comments nearby the 
relevant changes. These may add some noise to the webrev, if you prefer to look 
at the webrev without these changes a separate webrev is available here:

Webrev without typo fixes:
  http://cr.openjdk.java.net/~jwilhelm/8009032/webrev-no_typo_fix/


Bug: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8009032

Thanks,
/Jesper