Move LookupResult into crankshaft as that's now the only place where it's still used

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 612267b878d20eb4987a27cd2116b7335e0d342d..fd35c90e8d39049b7a5153339c697d84d90e6ca3 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -13565,16 +13565,6 @@ void JSArray::JSArrayUpdateLengthFromIndex(Handle<JSArray> array,
 }
 
 
-bool JSArray::IsReadOnlyLengthDescriptor(Handle<Map> jsarray_map) {
-  Isolate* isolate = jsarray_map->GetIsolate();
-  DCHECK(!jsarray_map->is_dictionary_map());
-  LookupResult lookup(isolate);
-  Handle<Name> length_string = isolate->factory()->length_string();
-  jsarray_map->LookupDescriptor(*length_string, &lookup);
-  return lookup.IsReadOnly();
-}
-
-
 bool JSArray::HasReadOnlyLength(Handle<JSArray> array) {
   LookupIterator it(array, array->GetIsolate()->factory()->length_string(),
                     LookupIterator::OWN_SKIP_INTERCEPTOR);