Move `org-xor' into "org-macs.el"

* lisp/org.el (org-xor): Move...
* lisp/org-macs.el: ... there.

lisp/org-macs.el

@@ -167,6 +167,14 @@ point nowhere."
   `(load ,file 'noerror nil nil 'mustsuffix))
 
 
+
+;;; Logic
+
+(defsubst org-xor (a b)
+  "Exclusive `or'."
+  (if a (not b) b))
+
+
 
 ;;; String manipulation
 

lisp/org.el

@@ -10020,10 +10020,6 @@ Note: this function also decodes single byte encodings like
 	       (char-to-string (string-to-number byte 16)))
 	     (cdr (split-string hex "%")) ""))
 
-(defun org-xor (a b)
-  "Exclusive or."
-  (if a (not b) b))
-
 (defun org-fixup-message-id-for-http (s)
   "Replace special characters in a message id, so it can be used in an http query."
   (when (string-match "%" s)