extract field formal contributor from prefixed element contributor

pkg/analysis_server/test/services/completion/dart/test_all.dart

Index: pkg/analysis_server/test/services/completion/dart/test_all.dart
diff --git a/pkg/analysis_server/test/services/completion/dart/test_all.dart b/pkg/analysis_server/test/services/completion/dart/test_all.dart
index 9d8d0617e4611fe2d52813b1742e2241f653227e..6d5c8366b12a3e550d8e7a17e923b28903a57afb 100644
--- a/pkg/analysis_server/test/services/completion/dart/test_all.dart
+++ b/pkg/analysis_server/test/services/completion/dart/test_all.dart
@@ -10,6 +10,7 @@ import '../../../utils.dart';
 import 'combinator_contributor_test.dart' as combinator_test;
 import 'arglist_contributor_test.dart' as arglist_test;
 import 'common_usage_sorter_test.dart' as common_usage_test;
+import 'field_formal_contributor_test.dart' as field_formal_contributor_test;
 import 'inherited_contributor_test.dart' as inherited_contributor_test;
 import 'keyword_contributor_test.dart' as keyword_test;
 import 'uri_contributor_test.dart' as uri_contributor_test;
@@ -21,6 +22,7 @@ main() {
     arglist_test.main();
     combinator_test.main();
     common_usage_test.main();
+    field_formal_contributor_test.main();
     inherited_contributor_test.main();
     keyword_test.main();
     uri_contributor_test.main();