If you're talking about Rosetta, it's not as clear that you'd see any successful attacks. It only runs at one CPU privilege level. And even in the browser sandbox escape versions Rosetta heavily uses AOT when it can, so your JS is probably not sharing a translation cache with much if any of the code you'd be attacking.

This is in contrast to Transmeta where the whole system more or less ran out of the one translation cache.

Now Nvidia Denver on the other hand...