Changed some hardcoded offset/alignment for classes in DMD, broke offsets for 64bits. Changed ClassInfo generation to no longer access the default initializer of ClassInfo, fixes problems with index mismatch.

module tangotests.switch2;

void main()
{
    int i=0;
    switch(i)
    {
    case 0:
        return;
    case 1:
        return;
    default:
        assert(0);
    }
}