Fix FixedArrayBase cast in NumberOfOwnElements

src/objects.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 13883 matching lines @@
   } else {
     return property_dictionary()->CopyKeysTo(storage, index, filter,
                                              NameDictionary::UNSORTED);
   }
 }
 
 
 int JSObject::NumberOfOwnElements(PropertyAttributes filter) {
   // Fast case for objects with no elements.
   if (!IsJSValue() && HasFastElements()) {
-    uint32_t length = IsJSArray() ?
-        static_cast<uint32_t>(
-            Smi::cast(JSArray::cast(this)->length())->value()) :
-        static_cast<uint32_t>(FixedArray::cast(elements())->length());
+    uint32_t length =
+        IsJSArray()
+            ? static_cast<uint32_t>(
+                  Smi::cast(JSArray::cast(this)->length())->value())
+            : static_cast<uint32_t>(FixedArrayBase::cast(elements())->length());
     if (length == 0) return 0;
   }
   // Compute the number of enumerable elements.
   return GetOwnElementKeys(NULL, filter);
 }
 
 
 int JSObject::NumberOfEnumElements() {
   return NumberOfOwnElements(static_cast<PropertyAttributes>(DONT_ENUM));
 }
@@ skipping 2950 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8