High traffic macros should detail this helpful addition.

...replacing `.cast().wrapping_offset().cast()` & similar code.

Rootless podman creates a separate user namespace, where an inner
`LOCAL_USER_ID` will map to a different subuid range on the host.
The "keep-id" mode maps the current UID directly into the container.

This makes `src/ci/docker/run.sh` work better for testing container
images on systems running podman, where "docker" is just a shim.

…sleywiser

Add GDB/LLDB pretty-printers for NonZero types

Add GDB/LLDB pretty-printers for `NonZero` types.
These pretty-printers were originally implemented for IntelliJ Rust by ``@Kobzol`` in intellij-rust/intellij-rust#5270.

Part of rust-lang#29392.

…riplett

Properly forward `ByRefSized::fold` to the inner iterator

cc ``@timvermeulen,`` who noticed this mistake in rust-lang#100214 (comment)

Fix wrong compiletest filters on Windows

As discussed in [rust-lang#79334](rust-lang#79334), when calling e.g.
```
python x.py test src/test/ui/expr/compound-assignment/eval-order.rs
```
on Windows, compiletest passes the filter `expr/compound-assignment/eval-order.rs` to libtest, which instead should be `expr\compound-assignment\eval-order.rs`, as that is the file found when collecting tests. This is what I fixed.

I'm not sure how to organize a test for this. Any suggestions?

… r=scottmcm

Make use of `[wrapping_]byte_{add,sub}`

These new methods trivially replace old `.cast().wrapping_offset().cast()` & similar code.
Note that [`arith_offset`](https://doc.rust-lang.org/std/intrinsics/fn.arith_offset.html) and `wrapping_offset` are the same thing.

r? ``@scottmcm``

_split off from #100746_

Extra documentation for new formatting feature

Documentation of this feature was added in rust-lang#90473 and released in Rust 1.58. However, high traffic macros did not receive new examples. Namely `println!()` and `format!()`.

The doc comments included in Rust are super important to the community- especially newcomers. I have met several other newbies like myself who are unaware of this recent (well about 7 months old now) update to the language allowing for convenient intra-string identifiers.

Bringing small examples of this feature to the doc comments of `println!()` and `format!()` would be helpful to everyone learning the language.

[Blog Post Announcing Feature](https://blog.rust-lang.org/2022/01/13/Rust-1.58.0.html)
[Feature PR](rust-lang#90473) - includes several instances of documentation of the feature- minus the macros in question for this PR

*This is my first time contributing to a project this large. Feedback would mean the world to me 😄*

---

*Recreated; I violated the [No-Merge Policy](https://rustc-dev-guide.rust-lang.org/git.html#no-merge-policy)*

… r=sanxiyn

Make some methods private

Diagnose missing includes in run-make tests

Use `--userns=keep-id` when "docker" is really podman

Rootless podman creates a separate user namespace, where an inner
`LOCAL_USER_ID` will map to a different subuid range on the host.
The "keep-id" mode maps the current UID directly into the container.

This makes `src/ci/docker/run.sh` work better for testing container
images on systems running podman, where "docker" is just a shim.