Fix some unittests for 64-bit asm. They were operating on int variables as if they were longs. This was causing asm1_1 to fail when compiled with -O3 because it was overwriting the spilled value of callee-saved register %rbx, which the runtime was using as a pointer value at the time.

module complex2;

void main()
{
    cdouble c = 3.0 + 0i;
    cdouble d = 2.0 + 0i;
    cdouble c1 = c + 3.0;
    cdouble c2 = c - 3.0i;
    cdouble c3 = c / 2.0;
}