Re: Building Emacs overflowed pure space

[Richard Stallman]

    The setq can be placed after, but the cdr can't, in case the `body' does
    a setcdr on it.

It is (cdr ,temp), referring to the uninterned symbol.
The body cannot refer to that uninterned symbol (that's the whole
point of using one).  So it is safe to take the cdr at the end.