auto merge of #7543 : sanxiyn/rust/newtype-immediates, r=catamorphism

Fix #6612. Rebase of #6725. Fixed an additional bug and added a test.

src/test/run-pass/newtype-temporary.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.
+
+struct Foo(uint);
+
+fn foo() -> Foo {
+    Foo(42)
+}
+
+fn main() {
+    assert_eq!(*foo(), 42);
+}