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 enum2;

void main()
{
    enum E {
        A,B
    }
    E e = E.B;
    assert(e == E.B);
}