Adjust the recent defmethod change.

Adjust the recent defmethod change.

(compile-or-load-defgeneric name) doesn't need the full eval-when
repertoire, only :compile-toplevel and :execute. :compile-toplevel for
subsequent forms and :execute for references within the body of
defmethod to itself. :load-toplevel is not needed since when the FASLs
are loaded no further processing is performed, this avoids the size
increase of the resulting FASLs.