Use a WeakCell in the CallIC type vector.

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"
 
@@ skipping 106 matching lines @@
   data->Initialize(arraysize(registers), registers, NULL);
 }
 
 
 void CreateAllocationSiteDescriptor::Initialize(
     CallInterfaceDescriptorData* data) {
   // cp: context
   // x2: feedback vector
   // x3: call feedback slot
   Register registers[] = {cp, x2, x3};
-  data->Initialize(arraysize(registers), registers, NULL);
+  Representation representations[] = {Representation::Tagged(),
+                                      Representation::Tagged(),
+                                      Representation::Smi()};
+  data->Initialize(arraysize(registers), registers, representations);
 }
 
 
+void CreateWeakCellDescriptor::Initialize(CallInterfaceDescriptorData* data) {
+  // cp: context
+  // x2: feedback vector
+  // x3: call feedback slot
+  // x1: tagged value to put in the weak cell
+  Register registers[] = {cp, x2, x3, x1};
+  Representation representations[] = {
+      Representation::Tagged(), Representation::Tagged(), Representation::Smi(),
+      Representation::Tagged()};
+  data->Initialize(arraysize(registers), registers, representations);
+}
+
+
 void StoreArrayLiteralElementDescriptor::Initialize(
     CallInterfaceDescriptorData* data) {
   Register registers[] = {cp, x3, x0};
   data->Initialize(arraysize(registers), registers, NULL);
 }
 
 
 void CallFunctionDescriptor::Initialize(CallInterfaceDescriptorData* data) {
   // x1  function    the function to call
   Register registers[] = {cp, x1};
@@ skipping 264 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