Force initialize the runtime module in Module::genLLVMModule. It is required for all non-trivial D modules anyway, so why load it lazily? This fixes run/typeid_83.d (DtoDeclareTypeInfo expects runtime to be initialized)

module tangotests.switch2;

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