Program Repair Shop

`compare_by_fc()`

I thought this function was really cleanly written
- I tried rewriting the logic a couple of different ways
- I don't think I got any significant improvements
But I do think we should get rid of the global variable:

     665  sub compare_by_fc
     666  {
        ...
     689        push @fc_LoL , [ @dups_found ]
     690            if (scalar (@dups_found) > 1);
        ...
     696  }

This becomes:

        sub compare_by_fc
        {
            my @fc_LoL;
        ...
     689        push @fc_LoL , [ @dups_found ]
     690            if (scalar (@dups_found) > 1);
        ...
            return @fc_LoL;
        }