syntax: obsolete the for Sized? syntax

src/test/compile-fail/obsolete-for-sized.rs

@@ -0,0 +1,17 @@
+// 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.
+
+// Test that we generate obsolete syntax errors around usages of `for Sized?`
+
+trait Foo for Sized? {} //~ ERROR obsolete syntax: for Sized?
+
+trait Bar for ?Sized {} //~ ERROR obsolete syntax: for Sized?
+
+fn main() { }