ref: 12219b1cfd13dff31498cd1acbfbf9c0bdf3d6d9 dir: /util.h/
void *emalloc(usize sz); void *ecalloc(ulong nel, usize elsz); void *erealloc(void *p, usize sz); char *estrndup(void *d, int n); char *estrdup(char *s);