Getting rid of translation-table-for-input (was: [Emacs-diffs] emacs-25 65575c2: Fix doc string of 'isearch-search-fun-function')

[Stefan Monnier]

> +STRING's characters are translated using `translation-table-for-input'
> +if that is non-nil.

Note that AFAIK translation-table-for-input has only ever been used to
implement "unification" in Emacs-21/22, which was rendered unnecessary in
Emacs-23 by the use of Unicode.

So translation-table-for-input (declared obsolete in 23.1) should
disappear in 26.1 (and IIUC nobody would have noticed if it had
disappeared earlier), and I don't think it's worthwhile adding mention
of it in docstrings nowadays.


        Stefan