bug#46240: Sorting order of read-char-by-name

[Juri Linkov]

>> Here is an option for this:
>
> Thanks, but why does the value of the defcustom _have_ to be a
> function?  Such defcustoms make it harder for users to customize them,
> because not everyone can write a sorting function.
>
> How about allowing simple values there, and if you really think we
> should allow a function, make that one of the possible values, but not
> require that the value be a function?

I agree.  If there is a need to add more values later,
such as grouping by Unicode blocks, then it would be
easier to add new values, not functions.