dart2js OldEmitter: Change to named holes in js output strings plus some extra clean-ups.

pkg/compiler/lib/src/js_backend/namer.dart

Index: pkg/compiler/lib/src/js_backend/namer.dart
diff --git a/pkg/compiler/lib/src/js_backend/namer.dart b/pkg/compiler/lib/src/js_backend/namer.dart
index 6ba5f267dadec52b1a04b9f3f04f2378356bfebc..c87708c235460eac9e089681d4c6382b74e66dcf 100644
--- a/pkg/compiler/lib/src/js_backend/namer.dart
+++ b/pkg/compiler/lib/src/js_backend/namer.dart
@@ -225,6 +225,9 @@ class Namer implements ClosureNamer {
   final String callPrefix = 'call';
   final String callCatchAllName = r'call$catchAll';
   final String reflectableField = r'$reflectable';
+  final String reflectionInfoField = r'$reflectionInfo';
+  final String reflectionNameField = r'$reflectionName';
+  final String metadataIndexField = r'$metadataIndex';
   final String defaultValuesField = r'$defaultValues';
   final String methodsWithOptionalArgumentsField =
       r'$methodsWithOptionalArguments';