Convert conservative_impl_trait.rs to compile-pass

src/test/run-pass/traits/conservative_impl_trait.rs

@@ -1,18 +0,0 @@
-// Copyright 2017 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.
-
-// run-pass
-// #39665
-
-fn batches(n: &u32) -> impl Iterator<Item=&u32> {
-    std::iter::once(n)
-}
-
-fn main() {}

src/test/run-pass/traits/conservative_impl_trait.stderr

@@ -1,8 +0,0 @@
-warning: function is never used: `batches`
-  --> $DIR/conservative_impl_trait.rs:14:1
-   |
-LL | fn batches(n: &u32) -> impl Iterator<Item=&u32> {
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: #[warn(dead_code)] on by default
-