Revert r20249, it seems the union trick works everywhere
Original commit message:
Very evil missuse of svn to test if AVOption and AVOption2 are compatible.
If this test triggers anywhere for anyone, revert this commit immedeatly.
Ill revert this in a day or 2, its just so we know beforehand if the idea
with the union is doable or not without breaking ABI/API.
Originally committed as revision 20264 to svn://svn.ffmpeg.org/ffmpeg/trunk