title: Error building project with make command, use of undeclared identifier '__compar_fn_t'
body: <p>I'm trying to build <a href="https://github.com/RedisBloom/RedisBloom#building-and-loading-redisbloom" rel="nofollow noreferrer">RedisBloom</a> and after running the make command I get the following error.</p>
  <pre><code>clang -dynamic -fcommon -g -ggdb -Wall -Wno-unused-function -g -ggdb -O2 -fPIC -std=gnu99 -D_GNU_SOURCE -I/Users/john/workspace/RedisBloom/contrib -I/Users/john/workspace/RedisBloom -I/Users/john/workspace/RedisBloom/src -I/Users/john/workspace/RedisBloom/deps/t-digest-c/src  -c -o /Users/john/workspace/RedisBloom/src/topk.o /Users/john/workspace/RedisBloom/src/topk.c
  /Users/john/workspace/RedisBloom/src/topk.c:223:50: error: use of undeclared identifier '__compar_fn_t'
      qsort(heapList, topk-&gt;k, sizeof(*heapList), (__compar_fn_t)cmpHeapBucket);
                                                   ^
  1 error generated.
  make: *** [/Users/dsesma/eclipse-workspace/RedisBloom/src/topk.o] Error 1
  </code></pre>
  <p>I'm using macOS Big Sur</p>