Fix rendering of const keyword for functions

src/test/rustdoc/const-fn.rs

@@ -0,0 +1,27 @@
+// Copyright 2017 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.
+
+#![feature(const_fn)]
+#![crate_name = "foo"]
+
+// @has foo/fn.bar.html
+// @has - '//*[@class="rust fn"]' 'pub const fn bar() -> '
+/// foo
+pub const fn bar() -> usize {
+    2
+}
+
+// @has foo/struct.Foo.html
+// @has - '//*[@class="method"]' 'const fn new()'
+pub struct Foo(usize);
+
+impl Foo {
+    pub const fn new() -> Foo { Foo(0) }
+}