Update CFE expectation for error test.

Also update the test name to follow test naming conventions (tests
with error expectations are named `*_error_test.dart`), and add a
copyright notice and test description.

Bug: https://github.com/dart-lang/sdk/issues/52202
Change-Id: I762dcbf6ebd02190250ccdd9767e6db29cac1d61
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/300322
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>

tests/language/patterns/issue52202_error_test.dart

diff --git a/tests/language/patterns/issue52202_error_test.dart b/tests/language/patterns/issue52202_error_test.dart
new file mode 100644
index 0000000..5163075
--- /dev/null
+++ b/tests/language/patterns/issue52202_error_test.dart
@@ -0,0 +1,18 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// Regression test for https://github.com/dart-lang/sdk/issues/52202.
+
+typedef A = int?;
+
+void f(x) {
+  switch (x) {
+    case A(foo: 0):
+//       ^
+// [analyzer] COMPILE_TIME_ERROR.UNCHECKED_USE_OF_NULLABLE_VALUE
+//            ^
+// [cfe] The getter 'foo' isn't defined for the class 'int?'.
+      break;
+  }
+}

tests/language/patterns/issue52202_test.dart

diff --git a/tests/language/patterns/issue52202_test.dart b/tests/language/patterns/issue52202_test.dart
deleted file mode 100644
index 40b9397..0000000
--- a/tests/language/patterns/issue52202_test.dart
+++ /dev/null
@@ -1,11 +0,0 @@
-typedef A = int?;
-
-void f(x) {
-  switch (x) {
-    case A(foo: 0):
-//       ^
-// [analyzer] COMPILE_TIME_ERROR.UNCHECKED_USE_OF_NULLABLE_VALUE
-// [cfe] unspecified
-      break;
-  }
-}