bug#25154: 25.1; Bindings in cl-letf are in reverse order

[Eli Zaretskii]

> From: Alex <agrambot@gmail.com>
> Cc: 25154@debbugs.gnu.org
> Date: Sat, 10 Dec 2016 12:05:40 -0600
> 
> > Isn't it true that the order of evaluation in a 'let' is unspecified?
> > If you want a particular order, use 'let*'.
> 
> I don't think so. See (info "(elisp) Local Variables"):
> 
>   All of the VALUE-FORMs in BINDINGS are evaluated in the order they
>   appear

That's the evaluation order.  Your code relies on the order of
_binding_ variables to values, which is unspecified.  Contrast the
above with the description of 'let*' below it.