rtant note:</strong> this set of generic functions is called at
macroexpansion time.  Methods are defined when loaded or evaluated,
not compiled.  You are responsible for ensuring that your
<code>expand-*</code> methods are defined when the <code>foreign-funcall</code> or
other forms that use them are compiled.  One way to do this is to put
the method definitions earlier in the file and inside an appropriate
<code>eval-when</code> form; another way is to always load a separate Lisp
or <acronym>FASL</acronym