Item movers need some fixes

Fixes rust-lang#8492

Author: dbofmmbt

crates/ide/src/move_item.rs

@@ -465,6 +465,48 @@ fn main() {}
         );
     }
 
+    #[test]
+    fn test_move_fn_up() {
+        check(
+            r#"
+fn main() {
+    println!("Hello, world!");
+}
+
+fn hi$0$0(arg: usize) {}
+            "#,
+            expect![[r#"
+fn hi$0(arg: usize) {}
+
+fn main() {
+    println!("Hello, world!");
+}
+            "#]],
+            Direction::Up,
+        );
+    }
+
+    #[test]
+    fn test_move_fn_down() {
+        check(
+            r#"
+fn hi$0$0(arg: usize) {}
+
+fn main() {
+    println!("Hello, world!");
+}
+            "#,
+            expect![[r#"
+fn main() {
+    println!("Hello, world!");
+}
+
+fn hi$0(arg: usize) {}
+            "#]],
+            Direction::Down,
+        );
+    }
+
     #[test]
     fn test_move_impl_up() {
         check(