Add regression test

Author: bkoropoff

src/test/run-pass/trait-object-safety.rs

@@ -0,0 +1,27 @@
+// Copyright 2014 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.
+
+// Check that object-safe methods are identified as such.  Also
+// acts as a regression test for #18490
+
+trait Tr {
+    // Static methods are always safe regardless of other rules
+    fn new() -> Self;
+}
+
+struct St;
+
+impl Tr for St {
+    fn new() -> St { St }
+}
+
+fn main() {
+    &St as &Tr;
+}