Provide CppHeap for Isolate initialization (#209)

Isolate::AttachCppHeap is about to be deprecated soon, the CppHeap
should be provided during Isolate initialization instead.

Author: gahaas

src/node_main_instance.cc

@@ -44,6 +44,8 @@ NodeMainInstance::NodeMainInstance(const SnapshotData* snapshot_data,
       isolate_params_(std::make_unique<Isolate::CreateParams>()),
       snapshot_data_(snapshot_data) {
   isolate_params_->array_buffer_allocator = array_buffer_allocator_.get();
+  isolate_params_->cpp_heap =
+      v8::CppHeap::Create(platform_, v8::CppHeapCreateParams{{}}).release();
 
   isolate_ =
       NewIsolate(isolate_params_.get(), event_loop, platform, snapshot_data);

src/node_worker.cc

@@ -181,6 +181,9 @@ class WorkerThreadData {
     SetIsolateCreateParamsForNode(&params);
     w->UpdateResourceConstraints(&params.constraints);
     params.array_buffer_allocator_shared = allocator;
+    params.cpp_heap =
+        v8::CppHeap::Create(w->platform_, v8::CppHeapCreateParams{{}})
+            .release();
     Isolate* isolate =
         NewIsolate(&params, &loop_, w->platform_, w->snapshot_data());
     if (isolate == nullptr) {