Remove compat code from gnus-uu and win

* lisp/gnus/gnus-util.el (gnus-image-type-available-p): Remove
compat code.

* lisp/gnus/gnus-uu.el (gnus-uu-tmp-dir): Remove compat code.

* lisp/gnus/gnus-win.el (gnus-frames-on-display-list): Remove.

lisp/gnus/gnus-util.el

@@ -1734,10 +1734,7 @@ lists of strings."
 ;;; Image functions.
 
 (defun gnus-image-type-available-p (type)
-  (and (fboundp 'image-type-available-p)
-       (if (fboundp 'display-images-p)
-	   (display-images-p)
-	 t)
+  (and (display-images-p)
        (image-type-available-p type)))
 
 (defun gnus-create-image (file &optional type data-p &rest props)

lisp/gnus/gnus-uu.el

@@ -217,11 +217,8 @@ Note that this variable can be used in conjunction with the
 
 ;; Various variables users may set
 
-(defcustom gnus-uu-tmp-dir
-  (cond ((fboundp 'temp-directory) (temp-directory))
-	((boundp 'temporary-file-directory) temporary-file-directory)
-	("/tmp/"))
-  "*Variable saying where gnus-uu is to do its work.
+(defcustom gnus-uu-tmp-dir temporary-file-directory
+  "Variable saying where gnus-uu is to do its work.
 Default is \"/tmp/\"."
   :group 'gnus-extract
   :type 'directory)

lisp/gnus/gnus-win.el

@@ -508,18 +508,11 @@ should have point."
       (mapcar (lambda (b) (delete-windows-on b t))
 	      (delq lowest-buf bufs)))))
 
-(eval-and-compile
-  (cond
-   ((fboundp 'frames-on-display-list)
-    (defalias 'gnus-frames-on-display-list 'frames-on-display-list))
-   (t
-    (defalias 'gnus-frames-on-display-list 'frame-list))))
-
 (defun gnus-get-buffer-window (buffer &optional frame)
   (cond ((and (null gnus-use-frames-on-any-display)
 	      (memq frame '(t 0 visible)))
 	 (car
-	  (let ((frames (gnus-frames-on-display-list)))
+	  (let ((frames (frames-on-display-list)))
 	    (gnus-remove-if (lambda (win) (not (memq (window-frame win)
 						     frames)))
 			    (get-buffer-window-list buffer nil frame)))))