Compile package:js.{rest, spread} helpers

tool/input_sdk/private/js_helper.dart

Index: tool/input_sdk/private/js_helper.dart
diff --git a/tool/input_sdk/private/js_helper.dart b/tool/input_sdk/private/js_helper.dart
index 34e08ea40efd4d2b6294c17ef7f052a919e404bf..a7a0d60627b77f15f8fe03b3e06d86b015b12bd8 100644
--- a/tool/input_sdk/private/js_helper.dart
+++ b/tool/input_sdk/private/js_helper.dart
@@ -24,7 +24,6 @@ class _Patch {
 
 const _Patch patch = const _Patch();
 
-
 /// Marks the internal map in dart2js, so that internal libraries can is-check
 // them.
 abstract class InternalMap {
@@ -176,7 +175,7 @@ class Primitives {
   /// In minified mode, uses the unminified names if available.
   static String objectToString(Object object) {
     // String name = objectTypeName(object);
-    String name = JS('String', 'dart.typeName(dart.realRuntimeType(#))', object); 
+    String name = JS('String', 'dart.typeName(dart.realRuntimeType(#))', object);
     return "Instance of '$name'";
   }