ref: 4886e44d6ea86d65f31eb6ecbfa8f82cac9c2fa0
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;
}