DEFCONSTANT and EQ

[Scott E. Fahlman <Fahlman@CMU-CS-C>]

On second thought, I would like to withdraw point 3 of my earlier
proposal, that byte-specifiers be slippery in the same sense that
numbers are.  In all of the cases that matter, the compiler can easily
detect that the byte specifier is being consumed by the function that is
using it; in all other cases, we can just refer to the special value in
the usual EQ-preserving way.  So we can get by with one less exceptional
case here.

Given this change, the only slippery objects are numbers (only the
consed ones) and character objects in implementations where those are
consed.  These are precisely the objects that are treated differently by
EQ and EQL.  So what Common Lisp really guarantees is that (EQL X X) but
not (EQ X X) in all cases.

-- Scott