anchor.diff:  (%SYSDEP
    "make select obj"
   
  - #+(or sbcl cmu18)
  + #+(or sbcl cmu18 cmu19)
    (defstruct SELECT
      (fds  nil)
      (cookies nil)
  
positive.code:      (push socket (select-value select))
       (push nil (select-cookies select)))
  
     #+(or sbcl cmu18)
     (%add-fd select (%socket-file-descriptor socket) select-rset)
  
     #+allegro
     (push (socket:socket-os-fd socket) (select-value select))
  
     ;; Default
     nil))
  
negative.code:        (max (select-maxn ,sobj) ,fd))
        (setf (,set ,sobj) (logior (,set ,sobj) (ash 1 ,fd))))))
  
  #+(or sbcl cmu18 cmu19)
  (defmacro %socket-file-descriptor (socket)
    (%SYSDEP
     "file descriptor for listener socket"
     #+clorb::db-sockets `(sockets:socket-file-descriptor ,socket)
     #+clorb::sb-bsd-sockets `(sb-bsd-sockets:socket-file-descriptor ,socket)
     #+(or cmu18 cmu19) socket))
  
  #+(or sbcl cmu18 cmu19)
  (defmacro %stream-fd (stream)
    (%SYSDEP
     "file descriptor for stream"
     #+(or cmu18 cmu19) `(system:fd-stream-fd ,stream)
     #+sbcl  `(sb-sys:fd-stream-fd ,stream)))
  
  #+(or sbcl cmu18 cmu19)
  (defmacro %unix-select (maxn rset wset xset timeout)
    `(#+sbcl sb-unix:unix-select #+(or cmu18 cmu19) unix:unix-select
             ,maxn ,rset ,wset ,xset ,timeout))
  
  
  