[builtins] Reduce lifetime of builtins constant table builder

Code generation introduces indirections if a builder exists (and the
serializer is active). These indirections are not necessary outside of
embedded builtins (e.g. in bytecode handlers), so let's reduce its
lifetime.

Bug: v8:6666
Change-Id: I57207012997786f599f79f0982da61eea26f3e22
Reviewed-on: https://chromium-review.googlesource.com/1059114
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53194}

src/isolate.cc

@@ -3034,18 +3034,26 @@ bool Isolate::Init(StartupDeserializer* des) {
   if (create_heap_objects) {
     // Terminate the partial snapshot cache so we can iterate.
     partial_snapshot_cache_.push_back(heap_.undefined_value());
-#ifdef V8_EMBEDDED_BUILTINS
-    if (serializer_enabled()) {
-      builtins_constants_table_builder_ =
-          new BuiltinsConstantsTableBuilder(this);
-    }
-#endif
   }
 
   InitializeThreadLocal();
 
   bootstrapper_->Initialize(create_heap_objects);
+
+#ifdef V8_EMBEDDED_BUILTINS
+  if (create_heap_objects && serializer_enabled()) {
+    builtins_constants_table_builder_ = new BuiltinsConstantsTableBuilder(this);
+  }
+#endif
   setup_delegate_->SetupBuiltins(this);
+#ifdef V8_EMBEDDED_BUILTINS
+  if (create_heap_objects && serializer_enabled()) {
+    builtins_constants_table_builder_->Finalize();
+    delete builtins_constants_table_builder_;
+    builtins_constants_table_builder_ = nullptr;
+  }
+#endif  // V8_EMBEDDED_BUILTINS
+
   if (create_heap_objects) heap_.CreateFixedStubs();
 
   if (FLAG_log_internal_timer_events) {
@@ -3072,14 +3080,6 @@ bool Isolate::Init(StartupDeserializer* des) {
     store_stub_cache_->Initialize();
     setup_delegate_->SetupInterpreter(interpreter_);
 
-#ifdef V8_EMBEDDED_BUILTINS
-    if (create_heap_objects && serializer_enabled()) {
-      builtins_constants_table_builder_->Finalize();
-      delete builtins_constants_table_builder_;
-      builtins_constants_table_builder_ = nullptr;
-    }
-#endif  // V8_EMBEDDED_BUILTINS
-
     heap_.NotifyDeserializationComplete();
   }
   delete setup_delegate_;