ref: a73d1bc55bf8d60f5cdd23c0f99080024a4c5f72
dir: /util.h/
#define Zns₀ (~0ULL) extern int debug; 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);