If AMD got taken over, then they would automatically lose their x86 license, as I believe it is a condition in their cross-licensing agreement. This is why I don't expect AMD to get bought in the near future.
It's a poison pill which means Intel themselves would be the only serious buyer.
[1] https://www.trustedreviews.com/news/amd-reveals-its-ready-to...
Which market regulators would never allow. This is even bigger in terms of monopoly than Nvidia trying to buy arm.