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.

class Foo
{
    this(int j)
    {
        i = pi = j;
    }

    int i;

private:

    int pi;
}

class Bar : Foo
{
    this(int j)
    {
        super(j);
        baz = 42;
    }

    int baz;
}

void func()
{
    auto bar = new Bar(12);
}

void main()
{
    func();
}