Fix issue-37887.rs

Author: pvdrz

tests/ui/imports/issue-37887.stderr renamed to tests/ui/imports/issue-37887.edition2015.stderr

@@ -1,5 +1,5 @@
 error[E0432]: unresolved import `test`
-  --> $DIR/issue-37887.rs:3:9
+  --> $DIR/issue-37887.rs:7:9
    |
 LL |     use test::*;
    |         ^^^^ use of unresolved module or unlinked crate `test`
@@ -10,7 +10,7 @@ LL + extern crate test;
    |
 
 error[E0658]: use of unstable library feature `test`
-  --> $DIR/issue-37887.rs:2:5
+  --> $DIR/issue-37887.rs:6:5
    |
 LL |     extern crate test;
    |     ^^^^^^^^^^^^^^^^^^

tests/ui/imports/issue-37887.edition2021.stderr

@@ -0,0 +1,23 @@
+error[E0658]: use of unstable library feature `test`
+  --> $DIR/issue-37887.rs:6:5
+   |
+LL |     extern crate test;
+   |     ^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
+   = help: add `#![feature(test)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error[E0658]: use of unstable library feature `test`
+  --> $DIR/issue-37887.rs:7:9
+   |
+LL |     use test::*;
+   |         ^^^^
+   |
+   = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
+   = help: add `#![feature(test)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0658`.

tests/ui/imports/issue-37887.rs

@@ -1,4 +1,9 @@
+//@ revisions: edition2015 edition2021
+//@[edition2015] edition: 2015
+//@[edition2021] edition: 2021
+//
 fn main() {
     extern crate test; //~ ERROR use of unstable
-    use test::*; //~ ERROR unresolved import
+    use test::*; //[edition2015]~ ERROR unresolved import
+                 //[edition2021]~^ ERROR use of unstable
 }