Move runtime helper for ToName conversion onto Object.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 468aca53ec301e552e2510a2902daaddf5c931c3..2d83ac04944882e597320a4f7ae88470a7e3752d 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -90,6 +90,18 @@ MaybeHandle<JSReceiver> Object::ToObject(Isolate* isolate,
 }
 
 
+MaybeHandle<Name> Object::ToName(Isolate* isolate, Handle<Object> object) {
+  if (object->IsName()) {
+    return Handle<Name>::cast(object);
+  } else {
+    Handle<Object> converted;
+    ASSIGN_RETURN_ON_EXCEPTION(isolate, converted,
+                               Execution::ToString(isolate, object), Name);
+    return Handle<Name>::cast(converted);
+  }
+}
+
+
 bool Object::BooleanValue() {
   if (IsBoolean()) return IsTrue();
   if (IsSmi()) return Smi::cast(this)->value() != 0;