Add names and support for preserialized data to serialization tests

tests/compiler/dart2js/serialization/resolved_ast_test.dart

Index: tests/compiler/dart2js/serialization/resolved_ast_test.dart
diff --git a/tests/compiler/dart2js/serialization/resolved_ast_test.dart b/tests/compiler/dart2js/serialization/resolved_ast_test.dart
index 9cba5af044699b494e6fa1af748160b519a0718b..46100767ea27a7c9ddf0d2bd0a76d207c4ff1da9 100644
--- a/tests/compiler/dart2js/serialization/resolved_ast_test.dart
+++ b/tests/compiler/dart2js/serialization/resolved_ast_test.dart
@@ -29,7 +29,7 @@ main(List<String> args) {
       Uri entryPoint = Uri.parse('memory:main.dart');
       // TODO(johnniwinther): Change to test all serialized resolved ast instead
       // only those used in the test.
-      Test test = TESTS.last;
+      Test test = TESTS.first;
       await check(serializedData, entryPoint, test.sourceFiles);
     }
   });