(make-comint): Error, if start-process is not fboundp.

lisp/comint.el

@@ -513,6 +513,8 @@ running process in that buffer, it is not restarted.  Optional third arg
 STARTFILE is the name of a file to send the contents of to the process.
 
 If PROGRAM is a string, any more args are arguments to PROGRAM."
+  (or (fboundp 'start-process)
+      (error "Multi-processing is not supported for this system"))
   (let ((buffer (get-buffer-create (concat "*" name "*"))))
     ;; If no process, or nuked process, crank up a new one and put buffer in
     ;; comint mode.  Otherwise, leave buffer and existing process alone.