ref: a6f27269f135c7f8f4d3ce30c9e15769f7201ed9
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;
}