> I know how to avoid the problem in my case, the bug does not really affect me. I posted it because I thought that the possibility to crash the interpreter is something to be avoided at all costs.

I fully agree with you.
However, that's a problem inherent to mmap(), and I don't think
there's a way to avoid this, but I could be wrong.

> I've found a few examples of handling non-restartable signals with longjmps, but not that familiar with the codebase to estimate how reliably it can be done on all supported platforms. I don't really know how this code would behave, say, on Windows.

You can't use longjmp from signal handlers. Well, you can, but 99% of
the code that does it is broken, because you can only call async-safe
functions from within a signal handler, and certainly can't run the
intepreter.