### Godot version

Beta 17, master

### System information

Windows 11

### Issue description

Godot gets a hard crash while attempting to code-complete for member `const` of a class.

### Steps to reproduce

```GDScript
enum E { V1 }

const e := E
```

And then type a `.` after the last `E`, which triggers code hints/auto-completion for subscripts based on `E` and causes a hard crash.

Does not happen for `var e := E.V1`.

### Minimal reproduction project

See above.
GDScriptParser::DataType type;
	type.type_source = GDScriptParser::DataType::ANNOTATED_EXPLICIT;
	type.kind = GDScriptParser::DataType::NATIVE;
	type.builtin_type = Variant::OBJECT;
	type.native_type = p_class_name;
	type.is_constant = true;
	type.is_meta_type = true;
	return type;
}
static GDScriptParser::DataType make_script_meta_type(const Ref<Script> &p_script) {
	GDScriptParser::DataType type;
	type.type_source = GDScriptParser::DataType::ANNOTATED_EXPLICIT;
	type.kind = GDScriptParser::DataType::SCRIPT;
	type.builtin_type = Variant::OBJECT;
	type.native_type = p_script->get_instance_base_type();
	type.script_type = p_script;
	type.script_path = p_script->get_path();
	type.is_constant = true;
	type.is_meta_type = true;
	return type;
}
static GDScriptParser::DataType make_enum_type(const StringName &p_enum_name, const String &p_base_name, const bool p_meta = false) {