RFR (XS): JDK-8081039: G1: Remove unused statistics code in G1NoteEndOfConcMarkClosure and G1ParNoteEndTask

[Bengt Rutisson]

Hi everyone,

Could I have a couple of reviews for this small cleanup?

http://cr.openjdk.java.net/~brutisso/8081039/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8081039

G1NoteEndOfConcMarkClosure and G1ParNoteEndTask keep track of some 
statistics such as max live bytes, freed bytes and some region claiming 
statistics. Of these only G1NoteEndOfConcMarkClosure::_freed_bytes is 
actually being used.

Thanks,
Bengt