Quieten --without-x compilation.

* lisp/term/common-win.el: Provide a feature.
* lisp/term/x-win.el (term/common-win): Require it.

lisp/term/common-win.el

@@ -419,4 +419,6 @@ the operating system.")
 	     (setq defined-colors (cons this-color defined-colors))))
       defined-colors)))
 
+(provide 'term/common-win)
+
 ;;; common-win.el ends here

lisp/term/x-win.el

@@ -72,6 +72,7 @@
 (if (not (fboundp 'x-create-frame))
     (error "%s: Loading x-win.el but not compiled for X" (invocation-name)))
 
+(require 'term/common-win)
 (require 'frame)
 (require 'mouse)
 (require 'scroll-bar)