Remove compatibility code for Emacs 22 and earlier

* yasnippet.el (region-active-p, locate-dominating-stop-dir-regexp)
(locate-dominating-file): Remove.

yasnippet.el

@@ -4928,62 +4928,6 @@ object satisfying `yas--field-p' to restrict the expansion to.")))
   (apply #'format (concat "[yas] " format-control) format-args))
 
 
-;;; Some hacks:
-;;
-;; The functions
-;;
-;; `locate-dominating-file'
-;; `region-active-p'
-;;
-;; added for compatibility in emacsen < 23
-(unless (>= emacs-major-version 23)
-  (unless (fboundp 'region-active-p)
-    (defun region-active-p ()  (and transient-mark-mode mark-active)))
-
-  (unless (fboundp 'locate-dominating-file)
-    (defvar locate-dominating-stop-dir-regexp
-      "\\`\\(?:[\\/][\\/][^\\/]+[\\/]\\|/\\(?:net\\|afs\\|\\.\\.\\.\\)/\\)\\'"
-      "Regexp of directory names which stop the search in `locate-dominating-file'.
-Any directory whose name matches this regexp will be treated like
-a kind of root directory by `locate-dominating-file' which will stop its search
-when it bumps into it.
-The default regexp prevents fruitless and time-consuming attempts to find
-special files in directories in which filenames are interpreted as hostnames,
-or mount points potentially requiring authentication as a different user.")
-
-    (defun locate-dominating-file (file name)
-      "Look up the directory hierarchy from FILE for a file named NAME.
-Stop at the first parent directory containing a file NAME,
-and return the directory.  Return nil if not found."
-      ;; We used to use the above locate-dominating-files code, but the
-      ;; directory-files call is very costly, so we're much better off doing
-      ;; multiple calls using the code in here.
-      ;;
-      ;; Represent /home/luser/foo as ~/foo so that we don't try to look for
-      ;; `name' in /home or in /.
-      (setq file (abbreviate-file-name file))
-      (let ((root nil)
-            try)
-        (while (not (or root
-                        (null file)
-                        ;; FIXME: Disabled this heuristic because it is sometimes
-                        ;; inappropriate.
-                        ;; As a heuristic, we stop looking up the hierarchy of
-                        ;; directories as soon as we find a directory belonging
-                        ;; to another user.  This should save us from looking in
-                        ;; things like /net and /afs.  This assumes that all the
-                        ;; files inside a project belong to the same user.
-                        ;; (let ((prev-user user))
-                        ;;   (setq user (nth 2 (file-attributes file)))
-                        ;;   (and prev-user (not (equal user prev-user))))
-                        (string-match locate-dominating-stop-dir-regexp file)))
-          (setq try (file-exists-p (expand-file-name name file)))
-          (cond (try (setq root file))
-                ((equal file (setq file (file-name-directory
-                                         (directory-file-name file))))
-                 (setq file nil))))
-        root))))
-
 ;;; Unloading
 
 (defvar unload-function-defs-list) ; loadhist.el