Strip_suffix won't break with new compiler versions. Anything explicitly imported takes precedence over the prelude, or else everything is a breaking change and would have to wait for an edition.
Switch to Rust 1.50 and now it's calling the stdlib strip_suffix silently, I actually wasn't expecting it to be silent, and obviously if they have the same exact behaviour (mine instead panics to show we're calling it) you wouldn't even notice, but it is a change.
https://rust.godbolt.org/z/4bsb91Krf is code which calls our strip_suffix in 1.40
Switch to Rust 1.50 and now it's calling the stdlib strip_suffix silently, I actually wasn't expecting it to be silent, and obviously if they have the same exact behaviour (mine instead panics to show we're calling it) you wouldn't even notice, but it is a change.