ref: d5ba7a743aa0a71de85332b403452fa3d498cb35
dir: /src/libc/stdlib/atexit.c/
#include <stdlib.h>
#include <errno.h>
#include "../libc.h"
#undef atexit
int
atexit(void (*fun)(void))
{
if (_exitn == _ATEXIT_MAX) {
errno = ENOMEM;
return -1;
}
_exitf[_exitn++] = fun;
return 0;
}