Snippets for angband 4.2.5 from Alpine riscv64

Sourced from https://build.alpinelinux.org/buildlogs/build-edge-riscv64/testing/angband/angband-4.2.5-r0.log.

• z-color.c:170:15: warning: comparison is always false due to limited range of data type [-Wtype-limits]
    170 |         if (c < 0) return (c);
        |               ^
  

• borg/borg4.c:2948:17: warning: the comparison will always evaluate as 'true' for the address of 'brands' will never be NULL [-Waddress]
   2948 |             if (item->brands)
        |                 ^~~~
  

• borg/borg6.c:5355:17: warning: the comparison will always evaluate as 'true' for the address of 'slays' will never be NULL [-Waddress]
   5355 |             if (!obj->slays || !obj->slays[i]) continue;
        |                 ^