Add regression test for #19163

Closes #19163.

Author: jooert

src/test/auxiliary/issue-19163.rs

@@ -0,0 +1,16 @@
+// Copyright 2015 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.
+
+#![crate_type = "lib"]
+
+#[macro_export]
+macro_rules! mywrite {
+    ($dst:expr, $($arg:tt)*) => ($dst.write_fmt(format_args!($($arg)*)))
+}

src/test/compile-fail/issue-19163.rs

@@ -0,0 +1,21 @@
+// Copyright 2015 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.
+
+// aux-build:issue-19163.rs
+
+#[macro_use] extern crate issue_19163;
+
+use std::io::Write;
+
+fn main() {
+    let mut v = vec![];
+    mywrite!(&v, "Hello world");
+ //~^ error: cannot borrow immutable borrowed content as mutable
+}