node-api: force env shutdown deferring behavior

The finalizer normally never gets called while a reference is strong.
However, during environment shutdown all finalizers must get called. In
order to unify the deferring behavior with that of a regular
finalization, we must force the reference to be weak when we call its
finalizer during environment shutdown.

Fixes: nodejs#37236
Co-authored-by: Chengzhong Wu <[email protected]>

Author: Gabriel Schulhof

src/js_native_api_v8.cc

@@ -270,6 +270,10 @@ class RefBase : protected Finalizer, RefTracker {
 
  protected:
   inline void Finalize(bool is_env_teardown = false) override {
+    // Force deferring behavior if the finalizer happens to delete this
+    // reference.
+    if (is_env_teardown && RefCount() > 0) _refcount = 0;
+
     if (_finalize_callback != nullptr) {
       _env->CallFinalizer(_finalize_callback, _finalize_data, _finalize_hint);
     }