CRR (S): 7121623: G1: always be able to reliably calculate the length of a forwarded chunked array

[Tony Printezis]

Hi all,

Can I have a couple of code review for this small change?

http://cr.openjdk.java.net/~tonyp/7121623/webrev.0/

The CR has a bit more explanation. The short version is that I'm now 
encoding the "start index of the next chunk" in the from-space length 
field of a chunked array (say *that* quickly!) as a negative value to 
always be able to distinguish it from the real length. This will 
simplify the code for the CR John is currently working on (6484965) but 
it's a small, self-contained change so it's good to get it code reviewed 
and pushed separately.

Tony