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 mini.norun_debug2;

import tango.stdc.stdlib : rand;

void main()
{
    size_t iter;
    while (iter < 25)
    {
        if (rand() % 20 == 10)
            *cast(int*)null = 0;
        ++iter;
    }
    assert(0);
}