add tests

src/liballoc/tests/vec.rs

@@ -131,6 +131,21 @@ fn test_extend_ref() {
     assert_eq!(v, [1, 2, 3, 4, 5, 6, 7]);
 }
 
+#[test]
+fn test_remove_item() {
+    let mut v = vec![1,2,3];
+    v.remove_item(&1);
+
+    assert_eq!(v.len(), 2);
+    assert_eq!(v, [2,3]);
+
+    let mut w = vec![1,2,3];
+    w.remove_item(&4);
+
+    assert_eq!(w.len(), 3);
+    w.remove_item(&4);
+}
+
 #[test]
 fn test_slice_from_mut() {
     let mut values = vec![1, 2, 3, 4, 5];