### Godot version

4.0-rc6

### System information

Fedora 37, Mesa Intel ADL GT2

### Issue description

Code that works as expected at runtime fails with Nil references to (assigned) exported vars in the editor:

![tool_global_position_error](https://user-images.githubusercontent.com/364501/222031460-ffb1ecbd-5175-4a42-8470-25285ba5f821.png)


### Steps to reproduce

Try to access the `global_position` of a `Node3D` that's assigned to an exported var.

See that it works at runtime.

See that it errors in the editor with:

> Invalid get index 'global_position' (on base: 'Nil').

### Minimal reproduction project

[tool_test.zip](https://github.com/godotengine/godot/files/10856640/tool_test.zip)

int parent_node = NO_PARENT_SAVED;
	if (save_node) {
		
		node_map[p_node] = idx;
		
		if (p_parent_idx == NO_PARENT_SAVED) {
			int sidx;
			if (nodepath_map.has(p_node->get_parent())) {
				sidx = nodepath_map[p_node->get_parent()];
			} else {
				sidx = nodepath_map.size();
				nodepath_map[p_node->get_parent()] = sidx;
			}
			nd.parent = FLAG_ID_IS_PATH | sidx;
		} else {
			nd.parent = p_parent_idx;
		}
		parent_node = idx;
		nodes.push_back(nd);
	}
	for (int i = 0; i < p_node->get_child_count(); i++) {
		Node *c = p_node->get_child(i);
		Error err = _parse_node(p_owner, c, parent_node, name_map, variant_map, node_map, nodepath_map);
		if (err) {
			return err;
		}
	}
	return OK;
}
Error SceneState::_parse_connections(Node *p_owner, Node *p_node, HashMap<StringName, int> &name_map, HashMap<Variant, int, VariantHasher, VariantComparator> &variant_map, HashMap<Node *, int> &node_map, HashMap<Node *, int> &nodepath_map) {