Request for review (XS): 7169056: Add gigabyte unit to proper_unit_for_byte_size() and byte_size_in_proper_unit()

[Bengt Rutisson]

Hi all,

I would like to push this simple change to allow for gigabyte units in 
some GC logging:
http://cr.openjdk.java.net/~brutisso/7169056/webrev.01/

Jesper and John Cuthbertson have already looked at it, so in theory I am 
all set to push this. But I would like to give other people a chance to 
have a look at the change before I push it.

Background
I attempted this change in a changeset that I pushed recently. It was 
not strictly related to those changes, so when I realized that I needed 
special treatment of 32 bit platforms I decided to push it as a separate 
change.

Thanks,
Bengt