Do not use new struct type where unnecessary.

src/api.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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 1369 matching lines @@
   } while (false)
 
 void FunctionTemplate::SetCallHandler(FunctionCallback callback,
                                       v8::Local<Value> data) {
   auto info = Utils::OpenHandle(this);
   EnsureNotInstantiated(info, "v8::FunctionTemplate::SetCallHandler");
   i::Isolate* isolate = info->GetIsolate();
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(isolate);
   i::HandleScope scope(isolate);
   i::Handle<i::Struct> struct_obj =
-      isolate->factory()->NewStruct(i::CALL_HANDLER_INFO_TYPE);
+      isolate->factory()->NewStruct(i::TUPLE2_TYPE);
   i::Handle<i::CallHandlerInfo> obj =
       i::Handle<i::CallHandlerInfo>::cast(struct_obj);
   SET_FIELD_WRAPPED(obj, set_callback, callback);
   if (data.IsEmpty()) {
     data = v8::Undefined(reinterpret_cast<v8::Isolate*>(isolate));
   }
   obj->set_data(*Utils::OpenHandle(*data));
   info->set_call_code(*obj);
 }
 
@@ skipping 436 matching lines @@
 
 
 void ObjectTemplate::SetCallAsFunctionHandler(FunctionCallback callback,
                                               Local<Value> data) {
   i::Isolate* isolate = Utils::OpenHandle(this)->GetIsolate();
   ENTER_V8_NO_SCRIPT_NO_EXCEPTION(isolate);
   i::HandleScope scope(isolate);
   auto cons = EnsureConstructor(isolate, this);
   EnsureNotInstantiated(cons, "v8::ObjectTemplate::SetCallAsFunctionHandler");
   i::Handle<i::Struct> struct_obj =
-      isolate->factory()->NewStruct(i::CALL_HANDLER_INFO_TYPE);
+      isolate->factory()->NewStruct(i::TUPLE2_TYPE);
   i::Handle<i::CallHandlerInfo> obj =
       i::Handle<i::CallHandlerInfo>::cast(struct_obj);
   SET_FIELD_WRAPPED(obj, set_callback, callback);
   if (data.IsEmpty()) {
     data = v8::Undefined(reinterpret_cast<v8::Isolate*>(isolate));
   }
   obj->set_data(*Utils::OpenHandle(*data));
   cons->set_instance_call_handler(*obj);
 }
 
@@ skipping 6752 matching lines @@
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   isolate->EnqueueMicrotask(Utils::OpenHandle(*microtask));
 }
 
 
 void Isolate::EnqueueMicrotask(MicrotaskCallback microtask, void* data) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
   i::HandleScope scope(isolate);
   i::Handle<i::CallHandlerInfo> callback_info =
       i::Handle<i::CallHandlerInfo>::cast(
-          isolate->factory()->NewStruct(i::CALL_HANDLER_INFO_TYPE));
+          isolate->factory()->NewStruct(i::TUPLE2_TYPE));
   SET_FIELD_WRAPPED(callback_info, set_callback, microtask);
   SET_FIELD_WRAPPED(callback_info, set_data, data);
   isolate->EnqueueMicrotask(callback_info);
 }
 
 
 void Isolate::SetAutorunMicrotasks(bool autorun) {
   SetMicrotasksPolicy(
       autorun ? MicrotasksPolicy::kAuto : MicrotasksPolicy::kExplicit);
 }
@@ skipping 1800 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8