Compilation error: implicit declaration of function 'pread64'

[dschepler]

On trying to build the package on my current (amd64 Linux) system, the compilation fails with:

../../../src/chm_lib.c: In function '_chm_fetch_bytes':
../../../src/chm_lib.c:727:15: error: implicit declaration of function 'pread64'; did you mean 'pread'? [-Wimplicit-function-declaration]
  727 |     readLen = pread64(h->fd, buf, (long)len, os);
      |               ^~~~~~~
      |               pread