CBLT-245:  remove special case for 64-bit, not needed with Xcode 5.1

Change-Id: I6927c27877648546070db7ef8afbeb43ffe1e77f
Reviewed-on: http://review.couchbase.org/35046
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>