(Re-)Build compiler and test ast

$ ./parrot -o abc.pbc abc.pir
$ ./parrot abc.pbc --target=past
> 3 + 5
"past" => PMC 'PAST::Block'  {
    [0] => PMC 'PAST::Op'  {
        <pirop> => "say"
        [0] => PMC 'PAST::Op'  {
            <pirop> => "add"
            [0] => PMC 'PAST::Val'  {
                <name> => "3"
                <vtype> => ".Integer"
            }
            [1] => PMC 'PAST::Val'  {
                <name> => "5"
                <vtype> => ".Integer"
            }
        }
    }
}