I think you _could_ reclaim your own domain if you wanted. You'd want to have a banner at the top with a clear note directing people to the new domain for the compiler explorer, so that people realize immediately that you're not domain squatting. A few people might put up a stink, but I'm pretty confident that most people wouldn't mind, especially since the tool itself is so useful. The name, for those who don't know it as your last name, is fun, but it isn't the reason people use the tool. Eventually, over enough time, people would start remembering the new URL, and you could shrink or remove the banner (and/or put a note elsewhere on the page).
Honestly "godbolt" is so memorable I can find it instantly even though I rarely use it; but "compiler-explorer" sounds like some generic SEO spam site that I'd probably never click on.
Even then the internet (and even books) are full of "godbolt" links, to the tool itself, to specific code samples. Till all those became irrelevant will take quite some time.
Links to specific examples are less of a problem as he could redirect those to compiler-explorer.com and just keep that redirect up forever. Really the only URL that would need to be "reclaimed" is https://godbolt.org/ and having a prominent link to compiler-explorer.com thee would solve that issue.
OTOH the godbolt domain is at least not actively used for a number of other TLDs getting one of those might be an easier option.
