Re: CL function's docstrings

[Richard Stallman]

    Thanks to the wonders of dynamic scoping this actually changes the
    semantics subtly.  In most cases you'll never be able to tell the
    difference, but when higer-order functions are involved it can be a problem;
    so if you do that, be careful.

We never told users it was ok to use these as free variables, so we
don't have to worry about that issue.  However, when changing the arg
names of a function in CL that calls other functions in CL, it would
be good to verify that the called functions don't use them as
free variables.

(It would be unclean to use them that way without defvar'ing them.)