src: avoid extra Persistent in DefaultTriggerAsyncIdScope

Instead of getting a reference to the main `AliasedBuffer`, which
would always unnecesarily allocate and destroy a `Persistent`
handle, store and use a reference to the owning object.

PR-URL: #23844
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Matheus Marchini <mat@mmarchini.me>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>

src/env-inl.h

@@ -186,20 +186,20 @@ inline void Environment::AsyncHooks::clear_async_id_stack() {
 inline Environment::AsyncHooks::DefaultTriggerAsyncIdScope
  ::DefaultTriggerAsyncIdScope(Environment* env,
  double default_trigger_async_id)
- : async_id_fields_ref_(env->async_hooks()->async_id_fields()) {
+ : async_hooks_(env->async_hooks()) {
  if (env->async_hooks()->fields()[AsyncHooks::kCheck] > 0) {
  CHECK_GE(default_trigger_async_id, 0);
  }
 
  old_default_trigger_async_id_ =
- async_id_fields_ref_[AsyncHooks::kDefaultTriggerAsyncId];
- async_id_fields_ref_[AsyncHooks::kDefaultTriggerAsyncId] =
+ async_hooks_->async_id_fields()[AsyncHooks::kDefaultTriggerAsyncId];
+ async_hooks_->async_id_fields()[AsyncHooks::kDefaultTriggerAsyncId] =
  default_trigger_async_id;
 }
 
 inline Environment::AsyncHooks::DefaultTriggerAsyncIdScope
  ::~DefaultTriggerAsyncIdScope() {
- async_id_fields_ref_[AsyncHooks::kDefaultTriggerAsyncId] =
+ async_hooks_->async_id_fields()[AsyncHooks::kDefaultTriggerAsyncId] =
  old_default_trigger_async_id_;
 }
 

src/env.h

@@ -487,7 +487,7 @@ class Environment {
  ~DefaultTriggerAsyncIdScope();
 
  private:
- AliasedBuffer<double, v8::Float64Array> async_id_fields_ref_;
+ AsyncHooks* async_hooks_;
  double old_default_trigger_async_id_;
 
  DISALLOW_COPY_AND_ASSIGN(DefaultTriggerAsyncIdScope);