feat(lib): backport with-memoization from 29

Ref: emacs-mirror/emacs@3c972723e4

lisp/doom-lib.el

@@ -838,5 +838,18 @@ The previous values will be be restored upon exit."
                 collect `(setenv ,(car var) ,(cadr var)))
      ,@body))
 
+;; Introduced in Emacs 29+
+(defbackport! defmacro with-memoization (place &rest code)
+  "Return the value of CODE and stash it in PLACE.
+If PLACE's value is non-nil, then don't bother evaluating CODE
+and return the value found in PLACE instead."
+  (declare (indent 1) (debug (gv-place body)))
+  (gv-letplace (getter setter) place
+    `(or ,getter
+         ,(macroexp-let2 nil val (macroexp-progn code)
+            `(progn
+               ,(funcall setter val)
+               ,val)))))
+
 (provide 'doom-lib)
 ;;; doom-lib.el ends here