### 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
"trait",
		"namespace",
		"yield",
		nullptr
	};
	const char **w = _reserved_words;
	while (*w) {
		p_words->push_back(*w);
		w++;
	}
	List<StringName> functions;
	GDScriptUtilityFunctions::get_function_list(&functions);
	for (const StringName &E : functions) {
		p_words->push_back(String(E));
	}
}
bool GDScriptLanguage::is_control_flow_keyword(String p_keyword) const {
	return p_keyword == "break" ||
			p_keyword == "continue" ||
			p_keyword == "elif" ||
			p_keyword == "else" ||
			p_keyword == "if" ||
			p_keyword == "for" ||
			p_keyword == "match" ||
			p_keyword == "pass" ||
			p_keyword == "return" ||
			p_keyword == "while";
}
bool GDScriptLanguage::handles_global_class_type(const String &p_type) const {