### 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.
expected_type = parser->current_function->get_datatype();
	}
	if (p_return->return_value != nullptr) {
		bool is_void_function = has_expected_type && expected_type.is_hard_type() && expected_type.kind == GDScriptParser::DataType::BUILTIN && expected_type.builtin_type == Variant::NIL;
		bool is_call = p_return->return_value->type == GDScriptParser::Node::CALL;
		if (is_void_function && is_call) {
			
			reduce_call(static_cast<GDScriptParser::CallNode *>(p_return->return_value), false, true);
		} else {
			reduce_expression(p_return->return_value);
		}
		if (is_void_function) {
			p_return->void_return = true;
			const GDScriptParser::DataType &return_type = p_return->return_value->datatype;
			if (is_call && !return_type.is_hard_type()) {
				String function_name = parser->current_function->identifier ? parser->current_function->identifier->name.operator String() : String("<anonymous function>");
				String called_function_name = static_cast<GDScriptParser::CallNode *>(p_return->return_value)->function_name.operator String();
#ifdef DEBUG_ENABLED
				parser->push_warning(p_return, GDScriptWarning::UNSAFE_VOID_RETURN, function_name, called_function_name);
#endif
				mark_node_unsafe(p_return);
			} else if (!is_call) {
				push_error("A void function cannot return a value.", p_return);
			}
			result.type_source = GDScriptParser::DataType::ANNOTATED_EXPLICIT;
			result.kind = GDScriptParser::DataType::BUILTIN;
			result.builtin_type = Variant::NIL;
			result.is_constant = true;
		} else {
			if (p_return->return_value->type == GDScriptParser::Node::ARRAY && has_expected_type && expected_type.has_container_element_type()) {