org: Rename for more consistency

* lisp/org.el (org-get-previous-sibling): Rename from
  org-get-last-sibling to be more consistent with the rest of Emacs.
  org-get-last-sibling stays as obsolete alias.

etc/ORG-NEWS

@@ -423,6 +423,12 @@ custom completion functions.
 
 *** Providing =directory-empty-p= from Emacs 28 as =org-directory-empty-p=
 
+*** =org-get-last-sibling= marked as obsolete
+
+Use =org-get-previous-sibling= instead.  This is just a rename to have
+a more consistent naming.  E.g. recall the pair of funtctions
+=next-line= / =previous-line=.
+
 * Version 9.4
 ** Incompatible changes
 *** Possibly broken internal file links: please check and fix

lisp/org-compat.el

@@ -772,6 +772,8 @@ context.  See the individual commands for more information."
 
 (define-obsolete-function-alias 'org-copy 'org-refile-copy "9.4")
 
+(define-obsolete-function-alias 'org-get-last-sibling 'org-get-previous-sibling "9.4")
+
 ;;;; Obsolete link types
 
 (eval-after-load 'ol

lisp/org.el

@@ -6727,8 +6727,8 @@ This function is the default value of the hook `org-cycle-hook'."
   ;; First, find a reasonable region to look at:
   ;; Start two siblings above, end three below
   (let* ((beg (save-excursion
-		(and (org-get-last-sibling)
-		     (org-get-last-sibling))
+		(and (org-get-previous-sibling)
+		     (org-get-previous-sibling))
 		(point)))
 	 (end (save-excursion
 		(and (org-get-next-sibling)
@@ -7620,7 +7620,7 @@ case."
   (setq arg (prefix-numeric-value arg))
   (org-preserve-local-variables
    (let ((movfunc (if (> arg 0) 'org-get-next-sibling
-		    'org-get-last-sibling))
+		    'org-get-previous-sibling))
 	 (ins-point (make-marker))
 	 (cnt (abs arg))
 	 (col (current-column))
@@ -20659,7 +20659,7 @@ This is like outline-next-sibling, but invisible headings are ok."
     (unless (or (eobp) (< (funcall outline-level) level))
       (point))))
 
-(defun org-get-last-sibling ()
+(defun org-get-previous-sibling ()
   "Move to previous heading of the same level, and return point.
 If there is no such heading, return nil."
   (let ((opoint (point))