Add some tests for const auto-deref.

const-autoderef.rs is based on an example from jdm in IRC (but the
quadruple-pointer part is entirely my fault).

Author: jld

src/test/run-pass/const-autoderef-newtype.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.
+
+struct S(&'static [int]);
+const C0: S = S([3]);
+const C1: int = C0[0];
+
+pub fn main() {
+    fail_unless!(C1 == 3);
+}

src/test/run-pass/const-autoderef.rs

@@ -0,0 +1,19 @@
+// 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.
+
+const A: [u8 * 1] = ['h' as u8];
+const B: u8 = (&A)[0];
+const C: &'static &'static &'static &'static [u8 * 1] = & & & &A;
+const D: u8 = (&C)[0];
+
+pub fn main() {
+    fail_unless!(B == A[0]);
+    fail_unless!(D == A[0]);
+}