`numpy.broadcast_shapes` is a new user-facing function
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`broadcast_shapes` gets the resulting shape from
broadcasting the given shape tuples against each other.

.. code:: python

    >>> np.broadcast_shapes((1, 2), (3, 1))
    (3, 2)

    >>> np.broadcast_shapes(2, (3, 1))
    (3, 2)

    >>> np.broadcast_shapes((6, 7), (5, 6, 1), (7,), (5, 1, 7))
    (5, 6, 7)