bug#53526: 29.0.50; macroexp-warn-and-return API change

[Stefan Monnier]

Package: Emacs
Version: 29.0.50


The following change in `macroexp.el` on `master` is not backward
compatible with the Emacs-28 API:

-(defun macroexp-warn-and-return (msg form &optional category compile-only)
+(defun macroexp-warn-and-return (arg msg form &optional category compile-only)

I suspect that the `arg` should be added at the end instead.  While I'm
here I also noticed that `byte-compile-form-stack` is a poor name for
a variable declared in `macroexp.el`.  It should either be renamed to
use the `macroexp-` prefix, or moved to `bytecomp.el` (and it probably
should have a double-hyphen, since I think it's not meant to be used by
anyone but us).


        Stefan