Auto merge of #27065 - marcusklaas:loop-label, r=nrc

This closes https://github.com/rust-lang/rust/issues/27042.

I'd love to know if there's a way to make a regression test for this!

src/test/compile-fail/issue-27042.rs

@@ -0,0 +1,26 @@
+// Copyright 2012-2014 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.
+
+// Regression test for #27042. Test that a loop's label is included in its span.
+
+fn main() {
+    let _: i32 =
+        'a: //~ ERROR mismatched types
+        loop { break };
+    let _: i32 =
+        'b: //~ ERROR mismatched types
+        while true { break };
+    let _: i32 =
+        'c: //~ ERROR mismatched types
+        for _ in None { break };
+    let _: i32 =
+        'd: //~ ERROR mismatched types
+        while let Some(_) = None { break };
+}