auto merge of #10833 : sfackler/rust/mut-pat, r=brson

Previously, if you wanted to bind a field mutably or by ref, you had to
do something like Foo { x: ref mut x }. You can now just do
Foo { ref mut x }.

Closes #6137

src/test/compile-fail/bind-struct-early-modifiers.rs

@@ -0,0 +1,17 @@
+// Copyright 2013 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.
+
+fn main() {
+    struct Foo { x: int }
+    match Foo { x: 10 } {
+        Foo { ref x: ref x } => {}, //~ ERROR unexpected `:`
+        _ => {}
+    }
+}