RFR (S): 8013791: G1: G1CollectorPolicy::initialize_flags() may set min_alignment > max_alignment

[Bengt Rutisson]

Hi everyone,

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

http://cr.openjdk.java.net/~brutisso/8013791/webrev.00/

For G1 it is important that the heap size is aligned by the region size. 
The ergonomics will pick CollectorPolicy::max_alignment() for aligning 
the heap, but this alignment is based on the card table rather than the 
region size.

This fix makes sure that we pick the larger alignment for the 
max_alignment value and it adds the same assert for the min and max 
alignments that is available in GenCollectorPolicy::initialize_flags().

Thanks,
Bengt