### Godot version

Godot 4.0 RC 2

### System information

Windows 11

### Issue description

As the title states you get no autocompletion when statically typing.
Of course the code still works, but it shouldn't be neccessary to cast an object to a type it already is.

### Steps to reproduce

1. Create child class with some functionality
![image](https://user-images.githubusercontent.com/100119945/220173809-0b2b2788-d986-4fa7-815c-444268d09c32.png)

2. Get node in parent class and call childs function
![image](https://user-images.githubusercontent.com/100119945/220174167-5ff3c8e9-863e-4fbd-a3cf-d88d34597b39.png)



### Minimal reproduction project

N/A
arghint += ", ";
		}
		if (p_arg_idx >= p_info.arguments.size()) {
			arghint += String::chr(0xFFFF);
		}
		arghint += "...";
		if (p_arg_idx >= p_info.arguments.size()) {
			arghint += String::chr(0xFFFF);
		}
	}
	arghint += ")";
	return arghint;
}
static String _make_arguments_hint(const GDScriptParser::FunctionNode *p_function, int p_arg_idx) {
	String arghint;
	if (p_function->get_datatype().builtin_type == Variant::NIL) {
		arghint = "void " + p_function->identifier->name.operator String() + "(";
	} else {
		arghint = p_function->get_datatype().to_string() + " " + p_function->identifier->name.operator String() + "(";
	}
	for (int i = 0; i < p_function->parameters.size(); i++) {
		if (i > 0) {
			arghint += ", ";
		}
		if (i == p_arg_idx) {
			arghint += String::chr(0xFFFF);
		}
		const GDScriptParser::ParameterNode *par = p_function->parameters[i];
		if (!par->get_datatype().is_hard_type()) {
			arghint += par->identifier->name.operator String() + ": Variant";