Support options like `extglob`

This script cannot be parsed using libbash. 

```sh
shopt -s extglob

case "/dev/udp/129.22.8.102/45" in
/dev/@(tcp|udp)/*/*)    echo ok 1;;
*)              echo bad 1;;
esac
```

The error is:
```
tests/extglob.tests: line 24: syntax error near unexpected token `('
tests/extglob.tests: line 24: `/dev/@(tcp|udp)/*/*)     echo ok 1;;'
```
