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 bug18;

struct S {
    int[9] i;
}

void main()
{
    int[9] i;
    auto s = S(i);
}