🚀 go-pugleaf

> Is there some reason this stuff doesn't use MAKE-LOAD-FORM et al, as
> defined in CLtL2?  The use of the two facilities is essentially the
> same, except that MAKE-LOAD-FORM handles circularities, and allows the
> user to extend the facility, for example, to deal with user-defined
> metaclasses.

Not all Common Lisps _have_ MAKE-LOAD-FORM.

> Also, given that CL compilers must handle "similarity as constants",
> as defined in CLtL2, this functionality can be implemented completely
> portably with a small amount of code.

CL compilers don't have to conform to CLtL II, and many of them
don't.  Some are planning to; others are not.  See page xiii:

   Until the day when an official ANSI Common Lisp standard
   emerges, the 1984 definition of Common Lisp will continue
   to be used widely.

It's unfortunate that this happens, but it's hard to avoid given
that work on the standard is still taking place.