### 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)

EditorPropertyNil *editor = memnew(EditorPropertyNil);
			return editor;
		} break;
		case Variant::BOOL: {
			EditorPropertyCheck *editor = memnew(EditorPropertyCheck);
			return editor;
		} break;
		case Variant::INT: {
			if (p_hint == PROPERTY_HINT_ENUM) {
				EditorPropertyEnum *editor = memnew(EditorPropertyEnum);
				Vector<String> options = p_hint_text.split(",");
				editor->setup(options);
				return editor;
			} else if (p_hint == PROPERTY_HINT_FLAGS) {
				EditorPropertyFlags *editor = memnew(EditorPropertyFlags);
				Vector<String> options = p_hint_text.split(",");
				editor->setup(options);
				return editor;
			} else if (p_hint == PROPERTY_HINT_LAYERS_2D_PHYSICS ||
					p_hint == PROPERTY_HINT_LAYERS_2D_RENDER ||
					p_hint == PROPERTY_HINT_LAYERS_2D_NAVIGATION ||
					p_hint == PROPERTY_HINT_LAYERS_3D_PHYSICS ||
					p_hint == PROPERTY_HINT_LAYERS_3D_RENDER ||
					p_hint == PROPERTY_HINT_LAYERS_3D_NAVIGATION ||
					p_hint == PROPERTY_HINT_LAYERS_AVOIDANCE) {
				EditorPropertyLayers::LayerType lt = EditorPropertyLayers::LAYER_RENDER_2D;
				switch (p_hint) {
					case PROPERTY_HINT_LAYERS_2D_RENDER:
						lt = EditorPropertyLayers::LAYER_RENDER_2D;
						break;