Resynthesize metadata from Kernel, when already supported.

pkg/analyzer/test/src/summary/resynthesize_common.dart

 // Copyright (c) 2015, 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.
 
 library test.src.serialization.elements_test;
 
 import 'dart:async';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_resolution_map.dart';
@@ skipping 8031 matching lines @@
 const dynamic a = null;
 --------------------
 unit: foo.dart
 
 ''');
   }
 
   test_metadata_prefixed_variable() async {
     addLibrarySource('/a.dart', 'const b = null;');
     var library = await checkLibrary('import "a.dart" as a; @a.b class C {}');
-    checkElementText(library, r'''
+    if (isSharedFrontEnd) {
+      checkElementText(library, r'''
+import 'a.dart' as a;
+@
+        b/*location: a.dart;b?*/
+class C {
+}
+''');
+    } else {
+      checkElementText(library, r'''
 import 'a.dart' as a;
 @
         a/*location: test.dart;a*/.
         b/*location: a.dart;b?*/
 class C {
 }
 ''');
+    }
   }
 
   test_metadata_simpleFormalParameter() async {
     var library = await checkLibrary('const a = null; f(@a x) {}');
     checkElementText(library, r'''
 const dynamic a = null;
 dynamic f(@
         a/*location: test.dart;a?*/ dynamic x) {}
 ''');
   }
@@ skipping 1977 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }