current `texinfo.tex` fails with `xetex`

[Werner LEMBERG]

Even the simplest input file `foo.texi`

```
\input texinfo
foo
@bye
```

processed with `PDFTEX=xetex texi2pdf foo.texi` fails with

```
This is XeTeX, Version 3.141592653-2.6-0.999994 (TeX Live 2022) (preloaded 
format=xetex)
 restricted \write18 enabled.
entering extended mode
(./z.texi (/home/wl/lilypond-book/texinfo.tex
Loading texinfo [version 2022-12-04.12]: pdf,
/home/wl/lilypond-book/texinfo.tex:1791: Illegal parameter number in definition
 of \pdflink.
<to be read again> 
                   2
l.1791   \def\pdflinkpage#1#2
                             {%
? 
/home/wl/lilypond-book/texinfo.tex:1791: Emergency stop.
<to be read again> 
                   2
l.1791   \def\pdflinkpage#1#2
                             {%
No pages of output.
Transcript written on z.log.
/usr/local/bin/texi2dvi: xetex exited with bad status, quitting.
```


    Werner