Correctly identify named early bound regions.

src/test/ui/nll/issue-52742.rs

@@ -0,0 +1,30 @@
+// Copyright 2012 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.
+
+#![feature(nll)]
+#![feature(in_band_lifetimes)]
+
+struct Foo<'a, 'b> {
+    x: &'a u32,
+    y: &'b u32,
+}
+
+struct Bar<'b> {
+    z: &'b u32
+}
+
+impl Foo<'_, '_> {
+    fn take_bar(&mut self, b: Bar<'_>) {
+        self.y = b.z
+        //~^ ERROR unsatisfied lifetime constraints
+    }
+}
+
+fn main() { }

src/test/ui/nll/issue-52742.stderr

@@ -0,0 +1,12 @@
+error: unsatisfied lifetime constraints
+  --> $DIR/issue-52742.rs:25:9
+   |
+LL |     fn take_bar(&mut self, b: Bar<'_>) {
+   |                 ---------         -- let's call this `'1`
+   |                 |
+   |                 lifetime `'2` appears in this type
+LL |         self.y = b.z
+   |         ^^^^^^^^^^^^ requires that `'1` must outlive `'2`
+
+error: aborting due to previous error
+