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.

extern(C) int printf(char*, ...);
void main()
{
    void* i;
    asm
    {
        mov EAX, FS:4;
        mov i, EAX;
    }
    printf("FS:4 = %p\n", i);
}