Review Request: Further AMD Family 15h Defaults

[Deneau, Tom]

Hi all,

Please review this patch which changes a few more defaults for the AMD family 15h processors.

The webrev is at

http://cr.openjdk.java.net/~tdeneau/bd-defaults-part2/webrev.01/

   * A previous patch made the default AllocationPrefetchStyle
     style 0 (no prefetch).  Here we add that if a different style
     is specified and a prefetch instruction type is not explicitly specified,
     the default prefetch instruction will be PREFETCHW.

   * UseXMMForArrayCopy and UseUnalignedLoadStores default to true

I do not have a bug id for this.

-- Tom Deneau, AMD