bug#1726: 23.0.60; end-of-sentence and non-breaking space

[Richard M Stallman]

    > Meanwhile, the Chinese and Chinese-derived character codes
    > do not follow Unicode.  So you can't enter them with \u.
    > What is the way to enter them?

    The problem at hand exists only for codes that are less than FF hex.

Maybe, but isn't there a similar problem for Chinese-derived
characters?  How does one specify these codes in a string constant?
Shouldn't there be some way?

Maybe there is never a need to do it; maybe we don't need to add a
feature for it.  But if we don't, we should document that there is
currently no way.