IWMC-Class-p bug & make-specializable

[Mike Thome <mthome@VAX.BBN.COM>]

	Just ran across this bug yesterday:  In the 3600 version of PCL,
the provided definition for IWMC-CLASS-P (in 3600-low.lisp, NOT the
defstruct-generated one in low.lisp) breaks when the function is passed
any sort of multidimensional array.  It assumes all arrays are vectors.
We've fixed it here by just adding an ARRAY-DIMENSIONS check, but we
haven't tested (or looked) to see if the resulting code is still faster
than that generated by the defstruct in low.lisp.

	Also, does anyone have a good way to do the equivalent of a
MAKE-SPECIALIZABLE on a setf-method?  I've hacked up some functions that
usually work, but if anyone already has a more robust (possibly to be
included in PCL distributions?) I'd prefer to use something that'll be
more standard.  Any idea how long it'll be until MAKE-SPECIALIZABLE
disappears/turns into a CLOS-defined function?

	While I'm on the subject of wishes - how 'bout a way to make
3600 FINs printable (i.e. non-recursive print-form) that is nicer than
setting *print-circle* (or whatever it is)???

	thanks,
		-mike thome (mthome@bbn.com)