Everybody does that to an extent- they'll just have to find some way of getting their CPU's (including their designs) directly from within China. This may not be as hard as people think with the Joint-Ownership thing that the Chinese government requires. I'm sure that chipmakers would love the business if they can get into China.

To address your comment- yes, they already do that, but because of loopholes, they probably won't have to develop a full stack.