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 complex3;

void main()
{
    cfloat c1 = 1f + 0i;
    cfloat c2 = 0f + 0i;
    c2 += 1f + 0i;
    assert(c1 == c2);
}