Add names and support for preserialized data to serialization tests

pkg/compiler/lib/src/serialization/resolved_ast_serialization.dart

Index: pkg/compiler/lib/src/serialization/resolved_ast_serialization.dart
diff --git a/pkg/compiler/lib/src/serialization/resolved_ast_serialization.dart b/pkg/compiler/lib/src/serialization/resolved_ast_serialization.dart
index 9b4e0d363455a39055f85af7a9e6dcc905dc0e51..ff8eef48b352e29f9ddfefa90d32b915f191dd2b 100644
--- a/pkg/compiler/lib/src/serialization/resolved_ast_serialization.dart
+++ b/pkg/compiler/lib/src/serialization/resolved_ast_serialization.dart
@@ -379,6 +379,8 @@ class ResolvedAstDeserializer {
       int charOffset = objectDecoder.getInt(Key.OFFSET);
       Token beginToken = getBeginToken(uri, charOffset);
       if (beginToken == null) {
+        // TODO(johnniwinther): Handle unfound tokens by adding an erronous
+        // resolved ast kind.
         reporter.internalError(
             element, "No token found for $element in $uri @ $charOffset");
       }