### 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.
src_native = GDScriptNativeClass::get_class_static();
			} else {
				src_native = p_source.native_type;
			}
			break;
		case GDScriptParser::DataType::SCRIPT:
			if (p_target.kind == GDScriptParser::DataType::CLASS) {
				
				return false;
			}
			if (p_source.is_meta_type) {
				src_native = p_source.script_type->get_class_name();
			} else {
				src_script = p_source.script_type;
				src_native = src_script->get_instance_base_type();
			}
			break;
		case GDScriptParser::DataType::CLASS:
			if (p_source.is_meta_type) {
				src_native = GDScript::get_class_static();
			} else {
				src_class = p_source.class_type;
				const GDScriptParser::ClassNode *base = src_class;
				while (base->base_type.kind == GDScriptParser::DataType::CLASS) {
					base = base->base_type.class_type;
				}
				src_native = base->base_type.native_type;
				src_script = base->base_type.script_type;
			}
			break;