enable memcached rss reporting on Windows

Change-Id: I123f64c6a3fbadccca8f9f72f7b351ec5b80464b
Reviewed-on: http://review.couchbase.org/42810
Reviewed-by: Venu Uppalapati <venumahesh@gmail.com>
Tested-by: Venu Uppalapati <venumahesh@gmail.com>