Update docs and tests for #[deriving(Show)].

src/test/compile-fail/deriving-span-Show-enum-struct-variant.rs

@@ -0,0 +1,26 @@
+// 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.
+
+// This file was auto-generated using 'src/etc/generate-keyword-span-tests.py'
+
+#[feature(struct_variant)];
+extern mod extra;
+
+
+struct Error;
+
+#[deriving(Show)]
+enum Enum {
+   A {
+     x: Error //~ ERROR
+   }
+}
+
+fn main() {}