refactor: avoid reordering attributes when restoring them

[fw-immunant]

• Fixes c2rust-refactor moves derive attributes #1426

including in the presence of multiple #[derive(...)] attributes interleaved with other attributes. No test at present; I'll look into adding one.

[fw-immunant]

I added a test but I'm not sure that these c2rust-refactor tests are actually run in CI.

It seems like we're not running scripts/test_rust_refactor.py.

[kkysen]

Can this just be written as a Rust #[test] instead? cargo test is run in CI.

[kkysen]

test_rust_refactor.py is pretty small (unlike test_translator.py), and it makes a lot of things more seamless to keep it all in cargo test.

[fw-immunant]

We do want to test end-to-end refactorer behavior here if possible, so if you have a suggestion on how to express that as a #[test] (e.g. setting up integrated snapshot testing for the refactorer), I'm all ears.

[kkysen]

Is this why stuff like #[c2rust::src_loc = "125:8"]#[derive(Copy, Clone)] is happening? I noticed that while testing crisp.

[fw-immunant]

Is this why stuff like #[c2rust::src_loc = "125:8"]#[derive(Copy, Clone)] is happening? I noticed that while testing crisp.

Yeah, this PR fixes that weird formatting.