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 switch2;
extern(C) int printf(char*, ...);

void main()
{
    int i = 2;
    switch(i)
    {
    case 0: assert(0);
    case 1,2: printf("hello world\n"); break;
    default: assert(0);
    }
}