Building from a584f48 with gcc 14.2.0:
malloc.c: In function 'alpha_memalign':
malloc.c:36:15: error: implicit declaration of function 'memalign' [-Wimplicit-function-declaration]
36 | void *ret = memalign(alignment, bytes);
| ^~~~~~~~
malloc.c:36:15: error: initialization of 'void *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
macOS does not have memalign and apparently does not need it either.
posix_memalign or malloc could be used, if needed.