Write the following functions in x64 assembly (in the Intel syntax):
int ft_strlen(char const *str);
int ft_strcmp(char const *s1, char const *s2);
char *ft_strcpy(char *dst, char const *src);
ssize_t ft_write(int fd, void const *buf, size_t nbyte);
ssize_t ft_read(int fd, void *buf, size_t nbyte);
char *ft_strdup(char const *s1);