### 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.
ERR_FAIL_INDEX(p_index, p_class->members.size());
	GDScriptParser::ClassNode::Member &member = p_class->members.write[p_index];
	if (p_source == nullptr && parser->has_class(p_class)) {
		p_source = member.get_source_node();
	}
	if (member.get_datatype().is_resolving()) {
		push_error(vformat(R"(Could not resolve member "%s": Cyclic reference.)", member.get_name()), p_source);
		return;
	}
	if (member.get_datatype().is_set()) {
		return;
	}
	if (!parser->has_class(p_class)) {
		String script_path = p_class->get_datatype().script_path;
		Ref<GDScriptParserRef> parser_ref = get_parser_for(script_path);
		if (parser_ref.is_null()) {
			push_error(vformat(R"(Could not find script "%s" (While resolving "%s").)", script_path, member.get_name()), p_source);
			return;
		}
		Error err = parser_ref->raise_status(GDScriptParserRef::PARSED);
		if (err) {
			push_error(vformat(R"(Could not resolve script "%s": %s (While resolving "%s").)", script_path, error_names[err], member.get_name()), p_source);
			return;
		}
		ERR_FAIL_COND_MSG(!parser_ref->get_parser()->has_class(p_class), R"(Parser bug: Mismatched external parser.)");
		GDScriptAnalyzer *other_analyzer = parser_ref->get_analyzer();
		GDScriptParser *other_parser = parser_ref->get_parser();
		int error_count = other_parser->errors.size();
		other_analyzer->resolve_class_member(p_class, p_index);