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 multiarr2;

void main()
{
    static float[1][2][3] arr;
    assert(arr[2][1][0] !<>= float.nan);
}