Add a run-pass test for recursive copyable stack closures.

src/test/run-pass/closure-bounds-recursive-stack-closure.rs

@@ -0,0 +1,31 @@
+// 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.
+
+// Ensures that it's legal to create a recursive stack closure as long as
+// its environment is copyable
+
+struct R<'self> {
+    // This struct is needed to create the
+    // otherwise infinite type of a fn that
+    // accepts itself as argument:
+    c: &'self fn:Copy(&R, uint) -> uint
+}
+
+fn main() {
+    // Stupid version of fibonacci.
+    let fib: &fn:Copy(&R, uint) -> uint = |fib, x| {
+        if x == 0 || x == 1 {
+            x
+        } else {
+            (fib.c)(fib, x-1) + (fib.c)(fib, x-2)
+        }
+    };
+    assert!(fib(&R { c: fib }, 7) == 13);
+}