Rollup of 3 pull requests Successful merges: - #126140 (Rename `std::fs::try_exists` to `std::fs::exists` and stabilize fs_try_exists) - #126318 (Add a `x perf` command for integrating bootstrap with `rustc-perf`) - #126552 (Remove use of const traits (and `feature(effects)`) from stdlib) r? `@ghost` `@rustbot` modify labels: rollup