ref: 3b8e22be8e01e95eddeeb9a1949b897df9b3f869
dir: /src/libc/string/memcpy.c/
#include <string.h>
#undef memcpy
void *
memcpy(void *restrict s1, const void *restrict s2, size_t n)
{
char *d = s1;
const char *s = s2;
while (n-- > 0)
*d++ = *s++;
return s1;
}