Revert "org.el: Improve performance of deletion commands"

This reverts commit 46df681336c83c826b367d2803f59560165bdeba.

The optimization broke folding fragility checks.

lisp/org.el

@@ -16156,19 +16156,18 @@ front of the next \"|\" separator, to keep the table aligned.  The table will
 still be marked for re-alignment if the field did fill the entire column,
 because, in this case the deletion might narrow the column."
   (interactive "p")
-  (org-fold-core-ignore-modifications
-    (save-match-data
-      (org-fold-check-before-invisible-edit 'delete-backward)
-      (if (and (= N 1)
-	       (not overwrite-mode)
-	       (not (org-region-active-p))
-	       (not (eq (char-before) ?|))
-	       (save-excursion (skip-chars-backward " \t") (not (bolp)))
-	       (looking-at-p ".*?|")
-	       (org-at-table-p))
-	  (progn (forward-char -1) (org-delete-char 1))
-        (backward-delete-char N)
-        (org-fix-tags-on-the-fly)))))
+  (save-match-data
+    (org-fold-check-before-invisible-edit 'delete-backward)
+    (if (and (= N 1)
+	     (not overwrite-mode)
+	     (not (org-region-active-p))
+	     (not (eq (char-before) ?|))
+	     (save-excursion (skip-chars-backward " \t") (not (bolp)))
+	     (looking-at-p ".*?|")
+	     (org-at-table-p))
+	(progn (forward-char -1) (org-delete-char 1))
+      (backward-delete-char N)
+      (org-fix-tags-on-the-fly))))
 
 (defun org-delete-char (N)
   "Like `delete-char', but insert whitespace at field end in tables.
@@ -16177,31 +16176,30 @@ front of the next \"|\" separator, to keep the table aligned.  The table will
 still be marked for re-alignment if the field did fill the entire column,
 because, in this case the deletion might narrow the column."
   (interactive "p")
-  (org-fold-core-ignore-modifications
-    (save-match-data
-      (org-fold-check-before-invisible-edit 'delete)
-      (cond
-       ((or (/= N 1)
-	    (eq (char-after) ?|)
-	    (save-excursion (skip-chars-backward " \t") (bolp))
-	    (not (org-at-table-p)))
-        (delete-char N)
-        (org-fix-tags-on-the-fly))
-       ((looking-at ".\\(.*?\\)|")
-        (let* ((update? org-table-may-need-update)
-	       (noalign (looking-at-p ".*?  |")))
-	  (delete-char 1)
-	  (org-table-with-shrunk-field
-	   (save-excursion
-	     ;; Last space is `org-table-separator-space', so insert
-	     ;; a regular one before it instead.
-	     (goto-char (- (match-end 0) 2))
-	     (insert " ")))
-	  ;; If there were two spaces at the end, this field does not
-	  ;; determine the width of the column.
-	  (when noalign (setq org-table-may-need-update update?))))
-       (t
-        (delete-char N))))))
+  (save-match-data
+    (org-fold-check-before-invisible-edit 'delete)
+    (cond
+     ((or (/= N 1)
+	  (eq (char-after) ?|)
+	  (save-excursion (skip-chars-backward " \t") (bolp))
+	  (not (org-at-table-p)))
+      (delete-char N)
+      (org-fix-tags-on-the-fly))
+     ((looking-at ".\\(.*?\\)|")
+      (let* ((update? org-table-may-need-update)
+	     (noalign (looking-at-p ".*?  |")))
+	(delete-char 1)
+	(org-table-with-shrunk-field
+	 (save-excursion
+	   ;; Last space is `org-table-separator-space', so insert
+	   ;; a regular one before it instead.
+	   (goto-char (- (match-end 0) 2))
+	   (insert " ")))
+	;; If there were two spaces at the end, this field does not
+	;; determine the width of the column.
+	(when noalign (setq org-table-may-need-update update?))))
+     (t
+      (delete-char N)))))
 
 ;; Make `delete-selection-mode' work with Org mode and Orgtbl mode
 (put 'org-self-insert-command 'delete-selection