### 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.
call_type = return_type;
	} else {
		bool found = false;
		
		if (base_type.kind == GDScriptParser::DataType::ENUM && base_type.is_meta_type) {
			push_error(vformat(R"*(Enums only have Dictionary built-in methods. Function "%s()" does not exist for enum "%s".)*", p_call->function_name, base_type.enum_type), p_call->callee);
		} else if (!p_call->is_super && callee_type != GDScriptParser::Node::NONE) { 
			GDScriptParser::IdentifierNode *callee_id;
			if (callee_type == GDScriptParser::Node::IDENTIFIER) {
				callee_id = static_cast<GDScriptParser::IdentifierNode *>(p_call->callee);
			} else {
				
				callee_id = static_cast<GDScriptParser::SubscriptNode *>(p_call->callee)->attribute;
			}
			if (callee_id) {
				reduce_identifier_from_base(callee_id, &base_type);
				GDScriptParser::DataType callee_datatype = callee_id->get_datatype();
				if (callee_datatype.is_set() && !callee_datatype.is_variant()) {
					found = true;
					if (callee_datatype.builtin_type == Variant::CALLABLE) {
						push_error(vformat(R"*(Name "%s" is a Callable. You can call it with "%s.call()" instead.)*", p_call->function_name, p_call->function_name), p_call->callee);
					} else {
						push_error(vformat(R"*(Name "%s" called as a function but is a "%s".)*", p_call->function_name, callee_datatype.to_string()), p_call->callee);
					}
#ifdef DEBUG_ENABLED
				} else if (!is_self && !(base_type.is_hard_type() && base_type.kind == GDScriptParser::DataType::BUILTIN)) {
					parser->push_warning(p_call, GDScriptWarning::UNSAFE_METHOD_ACCESS, p_call->function_name, base_type.to_string());
					mark_node_unsafe(p_call);
#endif
				}