### Godot version

4.0.beta10

### System information

Windows 11

### Issue description
UPDATE: This problem only occurs when the source code contains inner classes

Before 4.0.Beta9, I could get a GDScript instance by `GDScript.new()` and then set the `source_code` property and then `reload()`, but now it throws an error 
```
USER SCRIPT ERROR: Parse Error: Could not find script "".
   at: GDScript::reload (built-in:1644)
```
In my software, I use the above method when the user modifies the code text, and then read the godot log to implement real-time error checking of the custom user script editor. But now this functionality is completely broken

### Steps to reproduce

1. Create a GDScript instance by `GDScript.new()`
2. set the `source_code` property and then `reload()`

### Minimal reproduction project

N/A
const GDScript *sptr = script.ptr();
	while (sptr) {
		for (const KeyValue<StringName, GDScriptFunction *> &E : sptr->member_functions) {
			MethodInfo mi;
			mi.name = E.key;
			for (int i = 0; i < E.value->get_argument_count(); i++) {
				mi.arguments.push_back(PropertyInfo(Variant::NIL, "arg" + itos(i)));
			}
			p_list->push_back(mi);
		}
		sptr = sptr->_base;
	}
}
bool GDScriptInstance::has_method(const StringName &p_method) const {
	const GDScript *sptr = script.ptr();
	while (sptr) {
		HashMap<StringName, GDScriptFunction *>::ConstIterator E = sptr->member_functions.find(p_method);
		if (E) {
			return true;
		}
		sptr = sptr->_base;
	}
	return false;
}
Variant GDScriptInstance::callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) {