Don’t send the funding spend to onchaind if we detect it in inflights (aka. a splice). While we already prevented onchaind_funding_spent from being called directly, the call to wallet_channeltxs_add meant onchaind_funding_spent would be called *anyway* on restart. This is now fixed.
Additionally there was a potential for a race problem depending on the firing order of the channel depth and and funding spent events.
Instead of requiring these events fire in a specific order, we make a special “memory only” inflight object to prevent the race regardless of firing order.
Changelog-Fixed: Splice: bugfix for restart related race condition interacting with adversarial close detection.