correction on mlet & mlabels

[masinter.PA@Xerox.ARPA]

I apologize for having forgotten the resolution of the mlet and mlabels
issue.

There's a problem in the paper, in that it talks about specialization of
function-cells, as JAR points out. There is a simple definition of the
semantics of mlet: it lexically binds the symbol to a discriminator
who's default implementation is to invoke the global symbol-function.

E.g.,

(mlet ((move ((a window) b) body))
	mletforms)

is roughly

(let ((move (a b)
	(if (typep a window)
	    body
	    (funcall 'move a b))))
    mletbody)



Sorry for the time-warp (work on CommonLoops has been pretty intense,
and I remembered the debate and forgot the resolution!)

Larry