Snippets for fontconfig 2.18.1 from Alpine loongarch64

Sourced from https://build.alpinelinux.org/buildlogs/build-edge-loongarch64/main/fontconfig/fontconfig-2.18.1-r0.log.

• fcfreetype.c:1723:20: warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
   1723 |         canon_file = file;
        |                    ^
  

• fcint.h:172:47: warning: pointer 'leaves' may be used after 'realloc' [-Wuse-after-free]
    172 | #define FcOffsetToPtr(b, o, t)         ((t *)((uintptr_t)(b) + (ptrdiff_t)(o)))
        |                                               ^~~~~~~~~~~~~~