Auto merge of #1682 - RalfJung:rustup, r=RalfJung

rustup; test swap of element with itself

Cc rust-lang/rust#80682

Author: bors

rust-version

@@ -1 +1 @@
-0677d9729318441a1cdb0c74812ec4140fa4d35f
+dc1eee2f256efbd1d3b50b6b090232f81cac6d72

tests/run-pass/vec.rs

@@ -135,6 +135,11 @@ fn sort() {
     v.sort();
 }
 
+fn swap() {
+    let mut v = vec![1, 2, 3, 4];
+    v.swap(2, 2);
+}
+
 fn main() {
     assert_eq!(vec_reallocate().len(), 5);
 
@@ -161,4 +166,5 @@ fn main() {
     push_str_ptr_stable();
 
     sort();
+    swap();
 }