/*
 *  call-seq:
 *     dvector.reverse_each {|x| block } 
 *  
 *  Same as <code>Dvector#each</code>, but traverses _dvector_ in reverse
 *  order.
 *     
 *     a = Dvector[ 1, 0, -1 ]
 *     a.each {|x| print x, " " }
 *     
 *  produces:
 *     
 *      -1 0 1
 */ VALUE dvector_reverse_each(VALUE ary) {