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)

struct Foo;

Foo* foo()
{
    return null;
}

void main()
{
    Foo* f = foo();
    assert(f is null);
}