Unable to compile texinfo PDF with Chinese

[William Goodspeed]

Hello there,

I'm recently trying to translate Richard Stallman's c-intro-and-
reference (WIP). And I'm glad to hear that Chinese is supported in
texinfo 7.0 release.

I tested the Chinese sample document and it worked fine. But when it
comes to compile my translation of c-intro-and-reference, problems
appeared.

```
[goodspeed@meow c-intro-and-ref]$ make c.pdf
texi2pdf c.texi
This is XeTeX, Version 3.141592653-2.6-0.999995 (TeX Live 2023/Arch
Linux) (preloaded format=xetex)
 restricted \write18 enabled.
entering extended mode
(./c.texi (/home/goodspeed/Work/c-intro-and-ref/texinfo-zh.tex
(/usr/share/texmf-dist/tex/generic/zhspacing/zhspacing.sty
(/usr/share/texmf-dist/tex/generic/zhspacing/zhsusefulmacros.sty)
(/usr/share/texmf-dist/tex/generic/zhspacing/zhsmyclass.sty
(/usr/share/texmf-dist/tex/generic/zhspacing/zhsusefulmacros.sty)))
zhspacing installed.
(/home/goodspeed/Work/c-intro-and-ref/texinfo.tex
Loading texinfo [version 2023-08-13.14]: pdf, fonts, glyphs, page
headings,
tables, conditionals, indexing, sectioning, toc, environments, defuns,
macros,
cross references, insertions, (/usr/share/texmf-
dist/tex/generic/epsf/epsf.tex
This is `epsf.tex' v2.7.4 <14 February 2011>
) localization, formatting, microtype, and turning on texinfo input
format.))
Writing index file c.fn
./c.texi:44: TeX capacity exceeded, sorry [grouping levels=65535].
<XeTeXinterchartoks> ...enzh @relax @zhs@savefont 
                                                  @zhfont 
<to be read again> 
                   语
<argument> GNU C 语
                  言介绍
@titlefont #1->{@titlefonts @rm #1
                                  }
<argument> ...ignorespaces @titlefont {GNU C 语言介绍}
                                                  @unskip @hfil 
@centersub ...enalty @fi @line {@kern @leftskip #1
                                                  @kern @rightskip }
...
l.44 @center @titlefont{GNU C 语言介绍}
                                   
No pages of output.
Transcript written on c.log.
/usr/bin/texi2dvi: xetex exited with bad status, quitting.
make: *** [Makefile:15: c.pdf] Error 1
```

The source code is available at codeberg:

        https://codeberg.org/goodspeed/c-intro-and-ref