Auto merge of #28364 - petrochenkov:usegate, r=alexcrichton

Closes https://github.com/rust-lang/rust/issues/28075
Closes https://github.com/rust-lang/rust/issues/28388

r? @eddyb 
cc @brson

src/test/compile-fail/issue-28075.rs

@@ -0,0 +1,25 @@
+// Copyright 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.
+
+// Unstable entities should be caught in import lists
+
+// aux-build:lint_stability.rs
+
+#![allow(unused_imports)]
+
+extern crate lint_stability;
+
+use lint_stability::{unstable, deprecated}; //~ ERROR use of unstable library feature 'test_feature'
+//~^ WARNING use of deprecated item
+
+use lint_stability::unstable::{self as u}; //~ ERROR use of unstable library feature 'test_feature'
+
+fn main() {
+}

src/test/compile-fail/issue-28388-1.rs

@@ -0,0 +1,15 @@
+// Copyright 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.
+
+// Prefix in imports with empty braces should be resolved and checked privacy, stability, etc.
+
+use foo::{}; //~ ERROR failed to resolve. foo
+
+fn main() {}

src/test/compile-fail/issue-28388-2.rs

@@ -0,0 +1,19 @@
+// Copyright 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.
+
+// Prefix in imports with empty braces should be resolved and checked privacy, stability, etc.
+
+mod m {
+    mod n {}
+}
+
+use m::n::{}; //~ ERROR module `n` is private
+
+fn main() {}

src/test/compile-fail/issue-28388-3.rs

@@ -0,0 +1,20 @@
+// Copyright 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.
+
+// Prefix in imports with empty braces should be resolved and checked privacy, stability, etc.
+
+// aux-build:lint_stability.rs
+
+extern crate lint_stability;
+
+use lint_stability::UnstableStruct::{}; //~ ERROR use of unstable library feature 'test_feature'
+use lint_stability::StableStruct::{}; // OK
+
+fn main() {}

src/test/compile-fail/lint-output-format.rs

@@ -14,7 +14,8 @@
 #![feature(foo)] //~ ERROR unused or unknown feature
 
 extern crate lint_output_format; //~ ERROR use of unstable library feature
-use lint_output_format::{foo, bar};
+use lint_output_format::{foo, bar}; //~ ERROR use of unstable library feature
+//~^ WARNING use of deprecated item,
 
 fn main() {
     let _x = foo(); //~ WARNING #[warn(deprecated)] on by default