Omitted walker template for Coral Common Lisp 1.2.1

[Dan Rabin <rabin@arisia.xerox.com>]

Coral Common Lisp 1.2.1 has the additional special form
%stack-block, into which Macintosh toolbox calls from Lisp
expand.  The following walker-template definition seems to
correct the problem of the walker complaining of no template
found while trying to expand PCL macros:

#+Coral
(define-walker-template ccl:%stack-block walk-let)

This observation applies to 12/7/88 PCL.

--- Dan Rabin