ref: fbf19d0c31e7597f3e31c40b8c55f4dc0bd047dd 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);