### 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.
reduce_unary_op(static_cast<GDScriptParser::UnaryOpNode *>(p_expression));
			break;
		
		case GDScriptParser::Node::NONE:
		case GDScriptParser::Node::ANNOTATION:
		case GDScriptParser::Node::ASSERT:
		case GDScriptParser::Node::BREAK:
		case GDScriptParser::Node::BREAKPOINT:
		case GDScriptParser::Node::CLASS:
		case GDScriptParser::Node::CONSTANT:
		case GDScriptParser::Node::CONTINUE:
		case GDScriptParser::Node::ENUM:
		case GDScriptParser::Node::FOR:
		case GDScriptParser::Node::FUNCTION:
		case GDScriptParser::Node::IF:
		case GDScriptParser::Node::MATCH:
		case GDScriptParser::Node::MATCH_BRANCH:
		case GDScriptParser::Node::PARAMETER:
		case GDScriptParser::Node::PASS:
		case GDScriptParser::Node::PATTERN:
		case GDScriptParser::Node::RETURN:
		case GDScriptParser::Node::SIGNAL:
		case GDScriptParser::Node::SUITE:
		case GDScriptParser::Node::TYPE:
		case GDScriptParser::Node::VARIABLE:
		case GDScriptParser::Node::WHILE:
			ERR_FAIL_MSG("Reaching unreachable case");
	}
}
void GDScriptAnalyzer::reduce_array(GDScriptParser::ArrayNode *p_array) {