Computing involves a far broader base than just x86 now. The real threat involves ARM SOCs, one which both intel and AMD are trying to fight. x86 doesn't encompass all devices any longer, so you're just wrong. If AMD were to go bankrupt, and i'm not saying i'd want that to happen, but in all likelihood if it happened - it would happen with no intervention.
Hardly anyone buys a desktop now, fact of the matter is - computing is much broader now, and most consumers buy a tablet as their primary and only computing device. This isn't 2002 anymore where intel/microsoft had a hand in every computing device. Ten years ago what you're saying would be true. Today, it is simply irrelevant. PCs don't have the same hold over consumers as they did years ago. Therefore, the government would not have a vested interest in keeping them afloat.