Make an extension for an AdjustedArrayWindow specialization.

def window_specialization(typename):
    """Make an extension for an AdjustedArrayWindow specialization."""
    return Extension(
        'zipline.lib._{name}window'.format(name=typename),
        ['zipline/lib/_{name}window.pyx'.format(name=typename)],
        depends=['zipline/lib/_windowtemplate.pxi'],
    )