Now that templates instantiations are no longer emitted for all modules that even blink at them they seem to break due to being linkonce (if compiled with any optimization level > 0), so let's give them weak linkage instead. The difference is that unreferenced linkonce symbols can be deleted, while weak symbols need to be preserved.

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

class C
{
    void dump()
    {
        printf("C dumped\n");
    }
}

void heap()
{
    auto c = new C;
    c.dump();
}

void stack()
{
    scope c = new C;
    c.dump();
}

void main()
{
    heap();
    stack();
}