Ensure CopyElementsImpl is always executed so it fills in holes even if from_size is 0. Allow Fixed…

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 7db9175d41d6604d0f1f12ee2b92753fb412a618..b2efe2b2a84549799fb916f6edde90556bf6f984 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -2342,6 +2342,13 @@ void SeededNumberDictionary::set_requires_slow_elements() {
 // Cast operations
 
 
+FixedDoubleArray* FixedDoubleArray::castOrEmptyFixedArray(Object* object) {
+  ASSERT(object == HeapObject::cast(object)->GetHeap()->empty_fixed_array() ||
+         object->IsFixedDoubleArray());
+  return reinterpret_cast<FixedDoubleArray*>(object);
+}
+
+
 CAST_ACCESSOR(FixedArray)
 CAST_ACCESSOR(FixedDoubleArray)
 CAST_ACCESSOR(DescriptorArray)