On type error with long types, print an abridged type and write the full
type to disk.

Print the widest possible short type while still fitting in the
terminal.

…ger casts

Pointer-integer casts are required for conversion between `EXINF` (ITRON
task entry point parameter) and `*const ThreadInner`. Addresses the
deny-level lint `fuzzy_provenance_casts`.

Copied from `unsupported/io.rs`. Fixes build failure.

Addresses the warn-by-default lints `unused_imports` and
`unused_unsafe`.

This pattern seems to be considered illegal by Miri.

…retag into a separate function

This adds a new variant `ImplTraitContext::FeatureGated`, so we can
generalize the help for `return_position_impl_trait_in_trait` to also
work for `impl_trait_in_fn_trait_return`.

* Examples take up less screen height.
* Snippets from binary crates are prioritized.
* toggle-all-docs does not expand "More examples" sections.

…tton colors w/ themes

Resolves this docker warning:

```
[WARNING]: Empty continuation line found in:
    RUN apt-get update && apt-get install -y --no-install-recommends   g++   gcc-multilib   make   ninja-build   file   curl   ca-certificates   python2.7   python3.9   git   cmake   sudo   gdb   llvm-13-tools   llvm-13-dev   libedit-dev   libssl-dev   pkg-config   zlib1g-dev   xz-utils   nodejs     apt-transport-https software-properties-common &&     curl -s "https://packages.microsoft.com/config/ubuntu/$(lsb_release -rs)/packages-microsoft-prod.deb" > packages-microsoft-prod.deb &&     dpkg -i packages-microsoft-prod.deb &&     apt-get update &&     apt-get install -y powershell     && rm -rf /var/lib/apt/lists/*
Warning: : Empty continuation lines will become errors in a future release.
```

Detect long types in E0308 and write them to disk

On type error with long types, print an abridged type and write the full type to disk.

Print the widest possible short type while still fitting in the terminal.

…nce, r=thomcc

kmc-solid: `std::sys` code maintenance

Includes a set of changes to fix the [`*-kmc-solid_*`](https://doc.rust-lang.org/nightly/rustc/platform-support/kmc-solid.html) Tier 3 targets and make some other improvements.

- Address `fuzzy_provenance_casts` by using `expose_addr` and `from_exposed_addr` for pointer-integer casts
- Add a stub implementation of `is_terminal` (rust-lang#98070)
- Address `unused_imports` and `unused_unsafe`
- Stop doing `Box::from_raw(&*(x: Box<T>) as *const T as *mut T)`

…errors

Make nested RPIT inherit the parent opaque's generics.

Fixes rust-lang#105197

r? `@compiler-errors`

make retagging work even with 'unstable' places

This is based on top of rust-lang#105301. Only the last two commits are new.

While investigating rust-lang/unsafe-code-guidelines#381 I realized that we would have caught this issue much earlier if the add_retag pass wouldn't bail out on assignments of the form `*ptr = ...`.

So this PR changes our retag strategy:
- When a new reference is created via `Rvalue::Ref` (or a raw ptr via `Rvalue::AddressOf`), we do the retagging as part of just executing that address-taking operation.
- For everything else, we still insert retags -- these retags basically serve to ensure that references stored in local variables (and their fields) are always freshly tagged, so skipping this for assignments like `*ptr = ...` is less egregious.
r? `@oli-obk`

…provements, r=notriddle

Improve Rustdoc scrape-examples UI

This PR combines a few different improvements to the scrape-examples UI. See a live demo here: https://willcrichton.net/misc/scrape-examples/small-first-example/clap/struct.Arg.html

### 1. The first scraped example now takes up significantly less screen height.
Inserting the first scraped example takes up a lot of vertical screen space. I don't want this addition to overwhelm users, so I decided to reduce the height of the initial example in two ways: (A) the default un-expanded height is reduced from 240px (10 LOC) to 120px (5 LOC), and (B) the link to the example is now positioned *over* the example instead of *atop* the example (only on desktop though, not mobile). The changes to `scrape-examples.js` and `rustdoc.css` implement this fix.

Here is what an example docblock now looks like:

![Screen Shot 2022-12-06 at 10 02 21 AM](https://user-images.githubusercontent.com/663326/205987450-3940063c-5973-4a34-8579-baff6a43aa9b.png)

### 2. Expanding all docblocks will not expand "More examples".
The "More examples blocks" are huge, so fully expanding everything on the page would take up too much vertical space. The changes to `main.js` implement this fix. This is tested in `scrape-examples-toggle.goml`.

### 3. Examples from binary crates are sorted higher than examples from library crates.
Code that is written as an example of an API is probably better for learning than code that happens to use an API, but isn't intended for pedagogic purposes. Unfortunately Rustc doesn't know whether a particular crate comes from an example target (only Cargo knows this). But we can at least create a proxy that prefers examples from binary crates over library crates, which we know from `--crate-type`.

This change is implemented by adding a new field `bin_crate` in `Options` (see `config.rs`). An `is_bin` field has been added to the scraped examples metadata (see `scrape_examples.rs`). Then the example sorting metric uses `is_bin` as the first entry of a lexicographic sort on `(is_bin, example_size, display_name)` (see `render/mod.rs`).

Note that in the future we can consider adding another flag like `--scrape-examples-cargo-target` that would pass target information from Cargo into the example metadata. But I'm proposing a less intrusive change for now.

### 4. The scrape-examples help page has been updated to reflect the latest Cargo interface.

See `scrape-examples-help.md`.

r? `@notriddle`

P.S. once this PR and rust-lang/cargo#11450 are merged, then I think the scrape-examples feature is officially ready for deployment on docs.rs!

…-errors

Add help for `#![feature(impl_trait_in_fn_trait_return)]`

This adds a new variant `ImplTraitContext::FeatureGated`, so we can
generalize the help for `return_position_impl_trait_in_trait` to also
work for `impl_trait_in_fn_trait_return`.

cc rust-lang#99697

…e-rustdoc-errors, r=notriddle

Dont silently ignore rustdoc errors

I applied the suggestions from rust-lang#104995 and also checked the rustdoc-ui error but couldn't reproduce it.

r? `@notriddle`

…fix, r=jyn514

CI: add missing line continuation marker

Resolves this docker warning:

```
[WARNING]: Empty continuation line found in:
    RUN apt-get update && apt-get install -y --no-install-recommends   g++   gcc-multilib   make   ninja-build   file   curl   ca-certificates   python2.7   python3.9   git   cmake   sudo   gdb   llvm-13-tools   llvm-13-dev   libedit-dev   libssl-dev   pkg-config   zlib1g-dev   xz-utils   nodejs     apt-transport-https software-properties-common &&     curl -s "https://packages.microsoft.com/config/ubuntu/$(lsb_release -rs)/packages-microsoft-prod.deb" > packages-microsoft-prod.deb &&     dpkg -i packages-microsoft-prod.deb &&     apt-get update &&     apt-get install -y powershell     && rm -rf /var/lib/apt/lists/*
Warning: : Empty continuation lines will become errors in a future release.
```

Fix warning when libcore is compiled with no_fp_fmt_parse

Discovered when trying to compile Rust-for-Linux with Rust 1.66 beta.

It'll be helpful if this is backported to beta (should be trivial enough for backporting), so Rust-for-Linux's rust version bump wouldn't need to do `--cap-lints allow` for libcore.