update test

src/test/ui/suggestions/issue-51244.rs

@@ -0,0 +1,14 @@
+// Copyright 2018 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 ref my_ref @ _ = 0;
+    *my_ref = 0;
+}

src/test/ui/suggestions/issue-51244.stderr

@@ -0,0 +1,11 @@
+error[E0594]: cannot assign to immutable borrowed content `*my_ref`
+  --> $DIR/issue-51244.rs:13:5
+   |
+LL |     let ref my_ref @ _ = 0;
+   |         -------------- consider changing this to `ref mut my_ref @ _`
+LL |     *my_ref = 0;
+   |     ^^^^^^^^^^^ cannot borrow as mutable
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0594`.