bug#11011: Binding S-TAB

[Drew Adams]

> > 0. emacs -Q
> > 1. (global-set-key (kbd "S-TAB") (lambda () (message "FOO")))
> > 2. S-TAB
> >
> > And see the following error: "<backtab> is undefined"
> 
> You say "S-TAB", but that's not the key you pressed.  You pressed
> <backtab>, a function key, whereas S-TAB is a shifted ASCII character.
> Try "C-S-i" instead (which will also reveal a minor unrelated bug in
> your recipe ;-).

I was going to say the same thing, or similar.

`TAB` = `C-i`.

`TAB' is not the same as `<tab>'.

(kbd "S-<tab>") => [S-tab]
(kbd "S-TAB")   => [33554441]