Switch TypePointer::isunsigned from false to true, so CmpExp::toElem chooses the right operand for pointer comparisons. Fixes run/t/typeinfo_03_A,B,C,D.

void main()
{
    S t;
}

struct T
{
    int i;
    S* s;
}

struct S
{
    long i;
    T* t;
}