Rollup merge of #122786 - Enselic:remove_and_create_dir_all, r=onur-ozkan

compiletest: Introduce `remove_and_create_dir_all()` helper

The code

    let _ = fs::remove_dir_all(&dir);
    create_dir_all(&dir).unwrap();

is duplicated in 7 places. Let's introduce a helper.

Author: jhpratt