### 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
Variant name = p_name;
	const Variant *args[1] = { &name };
	const GDScript *sptr = script.ptr();
	while (sptr) {
		HashMap<StringName, GDScriptFunction *>::ConstIterator E = sptr->member_functions.find(GDScriptLanguage::get_singleton()->strings._property_get_revert);
		if (E) {
			Callable::CallError err;
			Variant ret = E->value->call(const_cast<GDScriptInstance *>(this), args, 1, err);
			if (err.error == Callable::CallError::CALL_OK && ret.get_type() != Variant::NIL) {
				r_ret = ret;
				return true;
			}
		}
		sptr = sptr->_base;
	}
	return false;
}
void GDScriptInstance::get_method_list(List<MethodInfo> *p_list) const {