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 tangotests.gc1;

void main()
{
    int[] arr;

    for (int i=0; i<100; ++i)
    {
        arr ~= new int[1000];
    }

    printf("arr.length = %u\n", arr.length);
}

extern(C) int printf(char*, ...);