librustc: Update AutoObject adjustment in writeback.

src/test/run-pass/issue-11612.rs

@@ -0,0 +1,30 @@
+// 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.
+
+// #11612
+// We weren't updating the auto adjustments with all the resolved
+// type information after type check.
+
+trait A {}
+
+struct B<'a, T> {
+    f: &'a T
+}
+
+impl<'a, T> A for B<'a, T> {}
+
+fn foo(_: &A) {}
+
+fn bar<G>(b: &B<G>) {
+    foo(b);       // Coercion should work
+    foo(b as &A); // Explicit cast should work as well
+}
+
+fn main() {}