Cleanup the core/object.dart file.

lib/compiler/implementation/lib/interceptors.dart

Index: lib/compiler/implementation/lib/interceptors.dart
diff --git a/lib/compiler/implementation/lib/interceptors.dart b/lib/compiler/implementation/lib/interceptors.dart
index fe9b03c493ed9415d5130c73b3ec40328dcba39e..1cb7fc62d7a92317aafed8afc5a771b8d18adfaf 100644
--- a/lib/compiler/implementation/lib/interceptors.dart
+++ b/lib/compiler/implementation/lib/interceptors.dart
@@ -653,16 +653,16 @@ isOdd(receiver) {
 
 get$toString(receiver) => () => toString(receiver);
 
-runtimeType(receiver) {
+get$runtimeType(receiver) {
   if (receiver is int) {
     return getOrCreateCachedRuntimeType('int');
   } else if (receiver is String) {
     return getOrCreateCachedRuntimeType('String');
   } else if (receiver is double) {
     return getOrCreateCachedRuntimeType('double');
-  } else if (receiver is List) {
+  } else if (isJsArray(receiver)) {
     return getOrCreateCachedRuntimeType('List');
   } else {
-    return UNINTERCEPTED(receiver.runtimeType());
+    return UNINTERCEPTED(receiver.runtimeType);
   }
 }