This makes the `Assume(&self.second == this)` check redundant
Co-authored-by: Ryan Ofsky <ryan@ofsky.org>
This is a partial backport of [[https://github.com/bitcoin/bitcoin/pull/30906 | core#30906]]
https://github.com/bitcoin/bitcoin/pull/30906/commits/fc8c282022e6ce4eb3ce526800a6ada3b4a2996d
Depends on D18806