NCONC and LAST of locatives

[David A. Moon <MOON at MIT-MC>]

The only recommended procedure for using locatives to build up a list is
the one in the example on page 157 of the red manual, i.e. rplacd the
previous tail and then setq the tail variable to the next tail.  Actually
what you should do is use LOOP and let it write the code, which will be as
efficient as anything you could write yourself and has the bonus of working
in all implementations (it writes different code for list collection for
Lisp machine, pdp10 Maclisp, Multics Maclisp, and VAX NIL).