(The bootstrap/beta compiler doesn't support them yet.)

…endering path

`rchunks_exact` is not a more optimized version of `chunks`, but of `rchunks`.

…tions, r=joshtriplett

Remove restrictions on compare-exchange memory ordering.

We currently don't allow the failure memory ordering of compare-exchange operations to be stronger than the success ordering, as was the case in C++11 when its memory model was copied to Rust. However, this restriction was lifted in C++17 as part of [p0418r2](https://wg21.link/p0418r2). It's time  we lift the restriction too.

| Success | Failure | Before | After |
|---------|---------|--------|-------|
| Relaxed | Relaxed | ✔️ | ✔️ |
| Relaxed | Acquire | ❌                | ✔️ |
| Relaxed | SeqCst  | ❌                | ✔️ |
| Acquire | Relaxed | ✔️ | ✔️ |
| Acquire | Acquire | ✔️ | ✔️ |
| Acquire | SeqCst  | ❌                | ✔️ |
| Release | Relaxed | ✔️ | ✔️ |
| Release | Acquire | ❌                | ✔️ |
| Release | SeqCst  | ❌                | ✔️ |
| AcqRel  | Relaxed | ✔️ | ✔️ |
| AcqRel  | Acquire | ✔️ | ✔️ |
| AcqRel  | SeqCst  | ❌                | ✔️ |
| SeqCst  | Relaxed | ✔️ | ✔️ |
| SeqCst  | Acquire | ✔️ | ✔️ |
| SeqCst  | SeqCst  | ✔️ | ✔️ |
| \*      | Release | ❌                | ❌                |
| \*      | AcqRel  | ❌                | ❌                |

Fixes rust-lang#68464

…-dead

Be more precise when suggesting removal of parens on unit ctor

* Fixes rust-lang#99240 by only suggesting to remove parens on path exprs, not arbitrary expressions with enum type
* Generalizes by suggesting removal of parens on unit struct, too, because why not?

…pertraits, r=oli-obk

Do not constraint TAITs when checking impl/trait item compatibility

Check out the UI test for the example.

Open to other approaches to fix this issue -- ideally we _would_ be able to collect this opaque type constraint in a way to use it in `find_opaque_ty_constraints`, so we can report a better mismatch error in the incompatible case, and just allow it in the compatible case. But that seems like a bigger refactor, so I wouldn't want to start it unless someone else thought it was a good idea.

cc rust-lang#99348
r? ``@oli-obk``

…-dead

Do not ICE when we have `-Zunpretty=expanded` with invalid ABI

Fixes rust-lang#99331

…tree-auto-expand, r=notriddle

Fix source code sidebar tree auto-expand

Here is the bug:

![Screenshot from 2022-07-17 13-32-00](https://user-images.githubusercontent.com/3050060/179397712-bfb1c279-0ed2-4cb5-aef5-05741921bcc3.png)

It was happening because as soon as we found the file (from the URL), every item following it was then opened, even if it wasn't supposed to.

The GUI test ensures that it doesn't happen by adding two nested levels and ensuring only this path is "open".

r? ``@notriddle``

Fix doc for `rchunks_exact`

`rchunks_exact` is not a more optimized version of `chunks`, but of `rchunks`.