[Issue 22010] Link error with mutually recursive SumType / struct with opEquals

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=22010

--- Comment #3 from João Lourenço <jlourenco5691 at gmail.com> ---
(In reply to Vladimir Panteleev from comment #2)
> Thanks but this is a reduced example meant to illustrate the compiler bug.

Yes, I mislead the issue and thought it was about SumType itself.

--