add ui test for rustdoc's deprecated attributes

Author: QuietMisdreavus

src/test/rustdoc-ui/deprecated-attrs.rs

@@ -0,0 +1,17 @@
+// Copyright 2018 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.
+
+// compile-pass
+
+#![doc(no_default_passes, passes = "collapse-docs unindent-comments")]
+
+struct SomeStruct;
+
+pub struct OtherStruct;

src/test/rustdoc-ui/deprecated-attrs.stderr

@@ -0,0 +1,9 @@
+warning: WARNING: the `#![doc(no_default_passes)]` attribute is considered deprecated
+  |
+  = warning: please see https://github.com/rust-lang/rust/issues/44136
+  = help: you may want to use `#![doc(document_private_items)]`
+
+warning: WARNING: the `#![doc(passes = "...")]` attribute is considered deprecated
+  |
+  = warning: please see https://github.com/rust-lang/rust/issues/44136
+