suggested compiler feature.

[Howard I. Cannon <HIC at MIT-MC>]

cc: GJC at MIT-MC, BUG-LISP at MIT-MC, BUG-LISPM at MIT-MC

I think that SETQ should know about atomic macros -- at least it
should give you a warning.  One of the major ideas behind atomic
macros is that you can use the atom without knowing whether or not
it will expand.  Note that the problem also arises when yo use an atomic
macro in a lambda-list.