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 enum1;

void main()
{
    enum {
        HELLO,
        WORLD
    }

    assert(HELLO == 0);
    assert(WORLD == 1);
}