On x32, tv_sec and tv_usec are in fact long long rather than the standard long,
and so in Python 2.x are automatically converted to Python longs, causing the
test to fail with:

    Failed example:
        test_itimer(10, 2)
    Expected:
        (10, 2)
    Got:
        (10L, 2L)

To fix this, we should explicitly call the int constructor.