enable ps stats collection on Windows

Change-Id: I5153d07ff35612c1d4e9003c099eff52ec4eea85
Reviewed-on: http://review.couchbase.org/42455
Reviewed-by: Venu Uppalapati <venumahesh@gmail.com>
Tested-by: Venu Uppalapati <venumahesh@gmail.com>