anchor.diff:    "Returns a pointer to a foreign symbol NAME."
     (prog1 (ignore-errors
              (ffi:foreign-address
  -            (ffi::foreign-library-variable
  -             name library nil nil)))))
  +            #+#.(cffi-sys::post-2.45-ffi-interface-p)
  +            (ffi::find-foreign-variable name nil library nil nil)
  +            #-#.(cffi-sys::post-2.45-ffi-interface-p)
  +            (ffi::foreign-library-variable name library nil nil)))))
  
positive.code:     `(,(find-cffi-symbol '#:foreign-library-handle)
         (,(find-cffi-symbol '#:get-foreign-library) ',name))))
  
  (defmacro %foreign-funcall (name args &key library calling-convention)
    "Invoke a foreign function called NAME, taking pairs of
  foreign-type/value pairs from ARGS.  If a single element is left
  
negative.code:     `(funcall
        (load-time-value
         (handler-case
             ,(%foreign-funcall-aux
               name
               `(ffi:parse-c-type
                 ',(c-function-type types rettype calling-convention))
               (if (eq library :default)
                   :default
                   (library-handle-form library)))
           (error (err)
             (warn "~A" err))))
        ,@fargs)))
  