Fixed a critical bug in the runtime, where _d_allocmemoryT would mark the memory block as having pointers (for scanning) opposite of what it should. So pointers would not be seen and freed. Should fix a bunch of regressions with AAs.

module bug47;

bool func(bool a, bool b)
{
    if (a) b = false;
    return b;
}

void main()
{
    assert(func(0,0) == 0);
    assert(func(0,1) == 1);
    assert(func(1,0) == 0);
    assert(func(1,1) == 0);
}