bug#10477: zap-to-char should allow picking from history

[Lars Ingebrigtsen]

jidanni@jidanni.org writes:

> zap-to-char should allow typing e.g., the up arrow to pick a recently used
> character, and then RET.
>
> Currently the only way is to type the actual character back in again!
> Even if hard to type CKS!
>
> Currently one gets 'Non-character input-event'.

I've now implemented this in Emacs 27 -- it was more code than expected,
so perhaps simple.el isn't the right place for it.  On the other hand,
`zap-to-char' is there, so perhaps that's the right place for it?

Or it could go to subr-x.el with an autoload -- `zap-to-char' probably
isn't the most used command ever, anyway, and I'm not sure
`read-char-with-history' has much utility outside that command.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no