bug#29838: 26.0; Elisp manual: describe standard-error sexps

[Drew Adams]

I think this is the main point: Users can easily see
(only) a message that shows a sexp, such as
`(args-out-of-range 9 9)', about which they have no
information.

If users never saw such messages then perhaps there
would be no need to describe such things as
`(args-out-of-range 9 9)'.  If they saw only nice
error messages such as "Args out of range: [1 2 3 4], -1"
then there would be no such problem.

If Emacs can be fixed so that users never see such
undescribed and unobvious messages then great.