typeck: Remove old diagnostic that refers to do.

src/test/compile-fail/missing-do.rs

@@ -1,19 +0,0 @@
-// Copyright 2012 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.
-
-// Regression test for issue #2783
-
-fn foo(f: ||) { f() }
-
-fn main() {
-    ~"" || 42; //~ ERROR binary operation `||` cannot be applied to type
-    foo || {}; //~ ERROR binary operation `||` cannot be applied to type
-    //~^ NOTE did you forget the `do` keyword for the call?
-}