 Though the frothy excitement of special purpose acquisition companies SPACs is going flat in the face of federal scrutiny, autonomous-vehicle software maker Aurora Innovation is reportedly close to a merger with a blank-check company started by one of its investors. Aurora, led by autonomous driving pioneer Chris Urmson, could agree to a business combination with Reinvent Technology Partners Y NASDAQ: RTPYU, the third SPAC launched by LinkedIn co-founder and Aurora investor Reid Hoiffman, social game developer Zynga Inc. NASDAQ: ZNGA founder Mark Pincus and managing partner Michael Thompson, the website TechCrunch reported Friday. 