update user module to 2021autumn version

user/src/bin/test1_write1.rs

@@ -0,0 +1,31 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+use user_lib::{write, STDOUT};
+const DATA_STRING: &str = "string from data section\n";
+
+/// 正确输出：
+/// string from data section
+/// strinstring from stack section
+/// strin
+/// Test write1 OK!
+
+#[no_mangle]
+pub fn main() -> i32 {
+    assert_eq!(write(1234, DATA_STRING.as_bytes()), -1);
+    assert_eq!(
+        write(STDOUT, DATA_STRING.as_bytes()),
+        DATA_STRING.len() as isize
+    );
+    assert_eq!(write(STDOUT, &DATA_STRING.as_bytes()[..5]), 5);
+    let stack_string = "string from stack section\n";
+    assert_eq!(
+        write(STDOUT, stack_string.as_bytes()),
+        stack_string.len() as isize
+    );
+    assert_eq!(write(STDOUT, &stack_string.as_bytes()[..5]), 5);
+    println!("\nTest write1 OK!");
+    0
+}