Fix a latent bug in the asm code. I think that technically, using "*m0" instead of "*0" allows LLVM to pick between using the same memory as output 0 and using a new memory location. (So far I haven't been able to construct a testcase that actually breaks because of this, though)

module union6;

struct S
{
    byte a;
    byte b;
}
union U
{
    byte a;
    byte b;
    S c;
}

void main()
{
    U u;
    auto a = u.c.b;
    //auto c = u.s.l;
}