Merge CoreTypes and CoreClasses into CommonElements.

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

Index: pkg/compiler/lib/src/js_backend/runtime_types.dart
diff --git a/pkg/compiler/lib/src/js_backend/runtime_types.dart b/pkg/compiler/lib/src/js_backend/runtime_types.dart
index e404cddb97adbcb9f8207b45d64ef11855249275..be1cb867299c7aee374e4f7d3da7a37540619b4e 100644
--- a/pkg/compiler/lib/src/js_backend/runtime_types.dart
+++ b/pkg/compiler/lib/src/js_backend/runtime_types.dart
@@ -263,7 +263,7 @@ class _RuntimeTypes implements RuntimeTypes {
     // TODO(karlklose): make this dependency visible from code.
     if (backend.helpers.jsArrayClass != null) {
       registerRtiDependency(
-          backend.helpers.jsArrayClass, compiler.coreClasses.listClass);
+          backend.helpers.jsArrayClass, compiler.commonElements.listClass);
     }
     // Compute the set of all classes and methods that need runtime type
     // information.