arm64 fix enum fields
arm64 fix enum fields

alexeyxo/protobuf-objc,E-B-Smith/protobuf-objc,alexeyxo/protobuf-objc,E-B-Smith/protobuf-objc,alexeyxo/protobuf-objc,E-B-Smith/protobuf-objc,alexeyxo/protobuf-objc,E-B-Smith/protobuf-objc