Rollup merge of #35505 - futile:test_29053, r=nikomatsakis

Add test for issue #29053

This PR adds a test for #29053 (currently fails on stage 0, but works with stage 1, as it should).

Fixes #29053

src/test/run-pass/issue-29053.rs

@@ -0,0 +1,21 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+    let x: &'static str = "x";
+
+    {
+        let y = "y".to_string();
+        let ref mut x = &*x;
+        *x = &*y;
+    }
+
+    assert_eq!(x, "x");
+}