CRR (XS): 7118202: G1: eden size unnecessarily drops to the minimum

[Tony Printezis]

Hi all,

I'd like a couple of code reviews for this very small change:

http://cr.openjdk.java.net/~tonyp/7118202/webrev.0/

It turns out that _max_rs_lengths gets smaller than _recorded_rs_lengths 
and rs_length_diff ends up huge which causes RSet lengths to be 
massively overpredicted.

We'll leave this small fix in until we work out why the problem happens 
(or most likely until we revamp the whole prediction code as we're 
planning to).

Thanks, again, to Thoms Schatzl for tracking this down.

Tony