Fix VarDecls for tuples. Closes #99. I've implemented it this way since it doesn't require any changes in the frontend. However, I think having TypeTuple expressed as LLVM struct types would make much more sense and open the door to tuple lvalues.

module bug56;

void main()
{
    int[] a;
    a = [1,2,3];
    {int[] b = [4,5,6];}
}