Move vec-cycle-wrapped test

Author: poliorcetics

library/alloc/tests/vec.rs

@@ -1870,3 +1870,44 @@ fn test_vec_cycle() {
     c3.v[0].set(Some(&c1));
     c3.v[1].set(Some(&c2));
 }
+
+#[test]
+fn test_vec_cycle_wrapped() {
+    struct Refs<'a> {
+        v: Vec<Cell<Option<&'a C<'a>>>>,
+    }
+
+    struct C<'a> {
+        refs: Refs<'a>,
+    }
+
+    impl<'a> Refs<'a> {
+        fn new() -> Refs<'a> {
+            Refs { v: Vec::new() }
+        }
+    }
+
+    impl<'a> C<'a> {
+        fn new() -> C<'a> {
+            C { refs: Refs::new() }
+        }
+    }
+
+    let mut c1 = C::new();
+    let mut c2 = C::new();
+    let mut c3 = C::new();
+
+    c1.refs.v.push(Cell::new(None));
+    c1.refs.v.push(Cell::new(None));
+    c2.refs.v.push(Cell::new(None));
+    c2.refs.v.push(Cell::new(None));
+    c3.refs.v.push(Cell::new(None));
+    c3.refs.v.push(Cell::new(None));
+
+    c1.refs.v[0].set(Some(&c2));
+    c1.refs.v[1].set(Some(&c3));
+    c2.refs.v[0].set(Some(&c2));
+    c2.refs.v[1].set(Some(&c3));
+    c3.refs.v[0].set(Some(&c1));
+    c3.refs.v[1].set(Some(&c2));
+}