bug#13177: 24.3.50; doc of `read-char-by-name'

[Eli Zaretskii]

> From: "Drew Adams" <drew.adams@oracle.com>
> Date: Sat, 15 Dec 2012 07:52:51 -0800
> Cc: 13177@debbugs.gnu.org
> 
> > As its docstring says, it also accepts a hexadecimal number
> > of Unicode code whose input can't use completion.
> 
> Yes, I know.  But the doc string also says that the hex numbers accepted are
> those corresponding to Unicode code points.  And it mentions hash notation for
> numbers, but in that case it does not say that those numbers too must 
> correspond
> to Unicode code points.

#xNNNNN can also specify 8-bit characters whose codepoints are outside
Unicode.

I have no idea whether this distinction is relevant to this function,
but since it talks about "Unicode code points", people who deal with
the documentation need to be aware of this subtlety.