Split up files with // ignore-tidy-filelength

[alex-griffiths]

Sorry it's taken me so long to get my act togethern on this, and that even with all the time, not much has been done. Hopefully what I've got here is at least acceptable.

One thing. When I'd build the compiler, I'd get some warnings about missing stability attributes. I wasn't sure the best way to fix this warning, so I've copied and pasted the stability attributes from the structs themselves. I hope this is okay. If not, I can try and fix it.

This is for #60302

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @KodrAus (or someone else) soon.

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[JohnTitor]

Please format the changes with ./x.py fmt, at least.

[petrochenkov]

@alex-griffiths
Could you avoid the changes in librustc_resolve?

If you'd like to do something in this direction, I'd suggest to start with moving #[test] functions into separate files in library/std (rust-lang/compiler-team#344, see #63207 for an example).
That's the change that certainly won't break any internal structure of the affected crates.

[alex-griffiths]

I'm so sorry. I didn't properly check that the changes I made at least built. I'll fix that now.

[petrochenkov]

@alex-griffiths
Could you squash commits as well, so that librustc_resolve changes are no longer in git history?
(This is not urgent, just something that needs to be done before the merge.)

[bors]

☔ The latest upstream changes (presumably #75815) made this pull request unmergeable. Please resolve the merge conflicts.

[KodrAus]

Thanks for working on this @alex-griffiths!

It looks like we've got some merge conflicts and a few broken doc links after the move:

core/str/fn.from_utf8_mut.html:25: broken link - core/str/struct.Utf8Error.html
core/str/fn.from_utf8.html:43: broken link - core/str/struct.Utf8Error.html
core/str/utf8/struct.Utf8Error.html:4: broken link - core/std/string/struct.String.html
core/str/utf8/struct.Utf8Error.html:65: broken link - core/std/char/constant.REPLACEMENT_CHARACTER.html
thread 'main' panicked at 'found some broken links', src/tools/linkchecker/main.rs:67:9

[tesuji]

You don't need to public these mods.

[JohnCSimon]

Ping from triage:
@alex-griffiths can you please address the comments, thank you.

[Dylan-DPC-zz]

hi @alex-griffiths thanks for taking the time to contribute. This has been inactive for a while, so I have to close it. If you wish and have the time in future you can open a new PR and we'll take it forward from there :) Thanks