bug#58830: 29.0.50; Build failure on master with cairo_ft_font_options_substitute

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Sam James <sam@gentoo.org> writes:

> Po Lu <luangruo@yahoo.com> writes:
>
>> Sam James <sam@gentoo.org> writes:
>>
>>> Emacs fails to compile from master (at commit
>>> e893fd10735239aeecae83805fc4cc6b37156a01)
>>> with an implicit function declaration
>>> (cairo_ft_font_options_substitute):
>>> ```
>>> xsettings.c: In function ‘apply_xft_settings’:
>>> xsettings.c:825:3: error: implicit declaration of function
>>> <E2><80>-Werror=implicit-function-declaration][]]
>>>   825 |   cairo_ft_font_options_substitute (options, pat);
>>>         |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>               |   cairo_font_options_status
>>> ```
>>>
>>
>> That's pretty odd.  AFAIU we only support builds with cairo with the
>> FreeType frontend present.
>>
>> Could you please send the contents of config.log?
>
> Sure. FWIW, it built a few hours ago (as you can see) with the same
> config.

Thanks, should be fixed now, please test.

I will fix this again differently after the Emacs 29 release, since the
Cairo specific code there may be unnecessary altogether.