ExtendStorageStub added, it is aimed for extending objects backing store when it runs out of space.

src/arm64/interface-descriptors-arm64.cc

 // Copyright 2012 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/v8.h"
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/interface-descriptors.h"
 
 namespace v8 {
 namespace internal {
 
 const Register CallInterfaceDescriptor::ContextRegister() { return cp; }
 
 
 const Register LoadDescriptor::ReceiverRegister() { return x1; }
 const Register LoadDescriptor::NameRegister() { return x2; }
 
 
 const Register VectorLoadICTrampolineDescriptor::SlotRegister() { return x0; }
 
 
 const Register VectorLoadICDescriptor::VectorRegister() { return x3; }
 
 
 const Register StoreDescriptor::ReceiverRegister() { return x1; }
 const Register StoreDescriptor::NameRegister() { return x2; }
 const Register StoreDescriptor::ValueRegister() { return x0; }
+const Register ExtendStorageDescriptor::MapRegister() {
+  return StoreDescriptor::NameRegister();
+}
 
 
 const Register ElementTransitionAndStoreDescriptor::MapRegister() { return x3; }
 
 
 const Register InstanceofDescriptor::left() {
   // Object to check (instanceof lhs).
   return x11;
 }
 
@@ skipping 319 matching lines @@
       Representation::Tagged(),    // holder
       Representation::External(),  // api_function_address
   };
   data->Initialize(arraysize(registers), registers, representations,
                    &default_descriptor);
 }
 }
 }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM64