Issue 7549: fix for invalid runtimeType.toString() for int, double, and

runtime/lib/object.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/bootstrap_natives.h"
 
 #include "vm/exceptions.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
 
@@ skipping 48 matching lines @@
 DEFINE_NATIVE_ENTRY(Object_runtimeType, 1) {
   const Instance& instance = Instance::CheckedHandle(arguments->NativeArgAt(0));
   const Type& type = Type::Handle(instance.GetType());
   return type.Canonicalize();
 }
 
 
 DEFINE_NATIVE_ENTRY(AbstractType_toString, 1) {
   const AbstractType& type =
       AbstractType::CheckedHandle(arguments->NativeArgAt(0));
-  return type.Name();
+  return type.UserVisibleName();
 }
 
 }  // namespace dart