Comment 3 for bug 661631

This only solves the problem with SBCL code, which only uses (setf ([f]documentation 'structure-accessor 'function) "...")

But since structures share the same closure for accessors, setting documentation of #'structure-accessor will mess it up. It's not used this way in the sources of SBCL, but external libraries do that (cxml, for example). So it's sufficient just to load a library with a single (setf documentation) on a structure accessor to mess up all other accessor docstrings throughout SBCL.