`impl<'_> IceCube<'_> {}` is now only one error in both editions

src/test/ui/underscore-lifetime/in-binder.Rust2015.stderr

-error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:12:6
-   |
-LL | impl<'_> IceCube<'_> {}
-   |      ^^ `'_` is a reserved lifetime name
-
-error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:17:15
-   |
-LL | struct Struct<'_> {
-   |               ^^ `'_` is a reserved lifetime name
-
-error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:23:11
-   |
-LL | enum Enum<'_> {
-   |           ^^ `'_` is a reserved lifetime name
-
-error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:29:13
-   |
-LL | union Union<'_> {
-   |             ^^ `'_` is a reserved lifetime name
-
-error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:35:13
-   |
-LL | trait Trait<'_> {
-   |             ^^ `'_` is a reserved lifetime name
-
-error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:40:8
-   |
-LL | fn foo<'_>() {
-   |        ^^ `'_` is a reserved lifetime name
-
-error[E0106]: missing lifetime specifier
-  --> $DIR/in-binder.rs:12:18
-   |
-LL | impl<'_> IceCube<'_> {}
-   |                  ^^ expected lifetime parameter
-
-error: aborting due to 7 previous errors
-
-Some errors occurred: E0106, E0637.
-For more information about an error, try `rustc --explain E0106`.

src/test/ui/underscore-lifetime/in-binder.rs

@@ -2,44 +2,34 @@
 //
 // Regression test for #52098.
 
-// revisions: Rust2015 Rust2018
-//[Rust2018] edition:2018
-
 struct IceCube<'a> {
     v: Vec<&'a char>
 }
 
 impl<'_> IceCube<'_> {}
-//[Rust2015]~^ ERROR `'_` cannot be used here
-//[Rust2015]~| ERROR missing lifetime specifier
-//[Rust2018]~^^^ ERROR `'_` cannot be used here
+//~^ ERROR `'_` cannot be used here
 
 struct Struct<'_> {
-//[Rust2015]~^ ERROR `'_` cannot be used here
-//[Rust2018]~^^ ERROR `'_` cannot be used here
+//~^ ERROR `'_` cannot be used here
     v: Vec<&'static char>
 }
 
 enum Enum<'_> {
-//[Rust2015]~^ ERROR `'_` cannot be used here
-//[Rust2018]~^^ ERROR `'_` cannot be used here
+//~^ ERROR `'_` cannot be used here
     Variant
 }
 
 union Union<'_> {
-//[Rust2015]~^ ERROR `'_` cannot be used here
-//[Rust2018]~^^ ERROR `'_` cannot be used here
+//~^ ERROR `'_` cannot be used here
     a: u32
 }
 
 trait Trait<'_> {
-//[Rust2015]~^ ERROR `'_` cannot be used here
-//[Rust2018]~^^ ERROR `'_` cannot be used here
+//~^ ERROR `'_` cannot be used here
 }
 
 fn foo<'_>() {
-    //[Rust2015]~^ ERROR `'_` cannot be used here
-    //[Rust2018]~^^ ERROR `'_` cannot be used here
+    //~^ ERROR `'_` cannot be used here
 }
 
 fn main() {}

src/test/ui/underscore-lifetime/in-binder.Rust2018.stderr → src/test/ui/underscore-lifetime/in-binder.stderr

 error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:12:6
+  --> $DIR/in-binder.rs:9:6
    |
 LL | impl<'_> IceCube<'_> {}
    |      ^^ `'_` is a reserved lifetime name
 
 error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:17:15
+  --> $DIR/in-binder.rs:12:15
    |
 LL | struct Struct<'_> {
    |               ^^ `'_` is a reserved lifetime name
 
 error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:23:11
+  --> $DIR/in-binder.rs:17:11
    |
 LL | enum Enum<'_> {
    |           ^^ `'_` is a reserved lifetime name
 
 error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:29:13
+  --> $DIR/in-binder.rs:22:13
    |
 LL | union Union<'_> {
    |             ^^ `'_` is a reserved lifetime name
 
 error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:35:13
+  --> $DIR/in-binder.rs:27:13
    |
 LL | trait Trait<'_> {
    |             ^^ `'_` is a reserved lifetime name
 
 error[E0637]: `'_` cannot be used here
-  --> $DIR/in-binder.rs:40:8
+  --> $DIR/in-binder.rs:31:8
    |
 LL | fn foo<'_>() {
    |        ^^ `'_` is a reserved lifetime name