feat(strdup): adding the function in asm

src/ft_strdup.s

@@ -0,0 +1,27 @@
+segment .note.GNU-stack
+
+extern ft_strcpy
+extern ft_strlen
+extern malloc
+
+section .text
+	global ft_strdup
+
+ft_strdup:
+	push    rbx								; save rbx
+	cmp     rdi, 0							; check s is NULL
+	je      .restore_exit					; exit (with restore of rbx) if true
+	mov     rbx, rdi						; save rdi value in rbx
+	call    ft_strlen						; call ft_strlen on rdi
+	lea     rdi, [rax + 1]					; calculation of the malloc size
+	call    malloc							; malloc is called return value on rax
+	test    rax, rax						; check the return value of malloc
+	je      .restore_exit					; exit (with restore of rbx) if true
+	mov     rdi, rax						; set the dest string (for ft_strcpy)
+	mov     rsi, rbx						; set the source string (for ft_strcpy)
+	pop     rbx								; restore rbx
+	jmp     ft_strcpy						; call ft_strcpy
+
+.restore_exit:
+	pop     rbx								; restore rbx
+	ret										; return rax (NULL)