fix #27363, support `@checked` on fields

pkg/analyzer/test/src/task/strong/checker_test.dart

Index: pkg/analyzer/test/src/task/strong/checker_test.dart
diff --git a/pkg/analyzer/test/src/task/strong/checker_test.dart b/pkg/analyzer/test/src/task/strong/checker_test.dart
index 920a2bba4de0f74cd4e9f9ee19161d127771f2f2..e647d641107432af6d547cd42d5b40d9a65e1f3d 100644
--- a/pkg/analyzer/test/src/task/strong/checker_test.dart
+++ b/pkg/analyzer/test/src/task/strong/checker_test.dart
@@ -532,6 +532,20 @@ class G_error extends E implements D {
     ''');
   }
 
+  void test_covariantOverride_fields() {
+    _addMetaLibrary();
+    checkFile(r'''
+import 'meta.dart';
+class A {
+  get foo => '';
+  set foo(_) {}
+}
+class B extends A {
+  @checked int foo;
+}
+    ''');
+  }
+
   void test_covariantOverride_leastUpperBound() {
     _addMetaLibrary();
     checkFile(r'''