Add test for #21922

Closes #21922.

src/test/run-pass/issue-21922.rs

@@ -0,0 +1,26 @@
+// 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.
+
+use std::ops::Add;
+fn show(z: i32) {
+    println!("{}", z)
+}
+fn main() {
+    let x = 23;
+    let y = 42;
+    show(Add::add( x,  y));
+    show(Add::add( x, &y));
+    show(Add::add(&x,  y));
+    show(Add::add(&x, &y));
+    show( x +  y);
+    show( x + &y);
+    show(&x +  y);
+    show(&x + &y);
+}