invalid memory reference (signal: 11) when using the new atomic registry API

[bkolobara]

This is a bit of a hard to reproduce bug. You will need to run some tests from https://github.com/lunatic-solutions/lunatic-rs in a loop to trigger it:

while true; do 
    cargo test --test registry
done

I believe the issue is in this unsafe code:

lunatic/crates/lunatic-registry-api/src/lib.rs

Lines 177 to 182 in 07454fb

	// Extend the lifetime of the lock, so it can be saved across host calls.
	// Safety:
	// The process state (containing the lock) can't outlive the `RwLock`,
	// which is global. This makes it safe to extend the lifetime.
	let registry_lock: RwLockWriteGuard<'static, HashMap<String, (u64, u64)>> =
	unsafe { transmute(registry_lock) };

One way to resolve this would be to move the "lookup and insert" operation to the process spawning function. In that case we would not require to hold onto a lock across host-guest-host calls.