Fix ICE with unresolved associated items in closures (fixes #28971)

src/test/compile-fail/issue-28971.rs

@@ -0,0 +1,27 @@
+// Copyright 2012-2015 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 should not cause an ICE
+
+enum Foo {
+    Bar(u8)
+}
+fn main(){
+    foo(|| {
+        match Foo::Bar(1) {
+            Foo::Baz(..) => (), //~ ERROR no associated
+            _ => (),
+        }
+    });
+}
+
+fn foo<F>(f: F) where F: FnMut() {
+    f();
+}