xorg build fails

[Adam Ciarciński <adam%NetBSD.org@localhost>]

Hello,

My current build keeps failing there:

[...]
/dist/xsrc/external/mit/fontconfig/dist/src/fccache.c:301:11: warning: implicit declaration of function '__UNVOLATILE' is invalid in C99 [-Wimplicit-function-declaration]
    free (__UNVOLATILE(lock));
          ^
/dist/xsrc/external/mit/fontconfig/dist/src/fccache.c:301:11: warning: incompatible integer to pointer conversion passing 'int' to parameter of type 'void *' [-Wint-conversion]
    free (__UNVOLATILE(lock));
          ^~~~~~~~~~~~~~~~~~
/usr/include/stdlib.h:143:18: note: passing argument to parameter here
void     free(void *);
                    ^
2 warnings generated.
Undefined symbols for architecture x86_64:
  "___UNVOLATILE", referenced from:
      _FcCacheFini in fccache.lo
ld: symbol(s) not found for architecture x86_64
[...]

This is 7.99.4 on Darwin with clang.
Please, fix. :-)

Kind regards,
Adam