hiroki yagi

Remove if-let macro to avoid conflict with emacs's if-let.

2

if-let is not used in j-mode and defined in emacs's default. https://github.com/emacs-mirror/emacs/blob/c10024911d6c225645c22e87a7326c13c0116ac6/lisp/emacs-lisp/subr-x.el#L158