(setf (apply #'foo ...) ...)

[Skef Wholey <Wholey@CMU-CS-C.ARPA>]

Just for the record (and to maybe make things epsilon easier for other
implementors), (setf (apply #'aref ...) ...) in Spice Lisp turns into a call to
Lisp::%Aset, which takes its arguments in the new-element-is-last order,
instead of the Zetalisp order.  That turned out to be just as easy for us.
Also, the Let bindings that Setf produces that it can't prove can go away are
examined by a general-purpose "Let optimizer" in our compiler, which does a
more thorough job of removing spurious bindings.

--Skef