Well there is this section in the contract for change of control, and there is a whole section on what change of control is too.
So if the controlling interest doesn't change then its ok, if not then there will be a breach of contract and the same rules apply as Intel will retain the 64 bit license. That's the way I took that. And if there is a buy out there is a change in controlling interest. With Bankruptcy its different, if AMD can't fulfill its obligations with in a certain amount of time, then the contract is broken. At that point you can probably expect that to happen because of the cash at hand is going to be 0, and at this point companies will probably try to buy AMD out as well.
A change of control is fairly clearly defined, but as far as I can see it is nowhere defined as a breach of contract.