`VecDeque`: `pop_front+push_back`

I naively thought that my (first) codegen tests were tested in the 48 minutes long CI I had in my PR but no. It therefore failed the rollup of 8 PRs. Anyone to help me fix them?

Error log: Rollup of 8 pull requests by matthiaskrgr · Pull Request #123143 · rust-lang/rust · GitHub

My bad codegen tests: Add invariant to VecDeque::pop_* that len < cap if pop successful by Philippe-Cholet · Pull Request #123089 · rust-lang/rust · GitHub

I finally fixed my PR. It has been merged and will be in rust 1.79.0.

Thank you all for this insightful discussion.