Self assignment doesn't work for bitwise ops
>>> arr = cl.array.zeros(q, 1, int)
>>> arr += 1
>>> arr
array([1])
>>> arr |= 1
>>> arr is None
True
>>> arr = cl.array.zeros(q, 1, int)
>>> arr += 1
>>> arr
array([1])
>>> arr |= 1
>>> arr is None
True