bug#28736: 24.5; doc of `push'

[Drew Adams]

> > The right question is why is it a problem to document this?
> 
> <Shrug> Because we don't want to guarantee the return value won't
> change in the future?

Are you sure?  When was that decided?  Just now?

Why would we want to do that?  Gratuitously acting different
from Common Lisp (and all other Lisps?) in this case wouldn't
seem to be advantageous.  Do you see a good reason to do that?

And why "<Shrug>"?  I wonder if your answer might have been
different if a different person had filed this bug...