Without this change it's going through `&mut impl Iterator`, which handles `?Sized` and thus currently can't forward generics.

Here's the test added, to see that it fails before this PR (once a new enough nightly is out): https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=462f2896f2fed2c238ee63ca1a7e7c56

This allows consts of type Ordering to be used in patterns, and (with feature(adt_const_params)) allows using Orderings as const generic parameters.

Added test in library/core/tests/cmp.rs that ensures that `const`s of type `Ordering`s can be used in patterns.

Remove else { None } in favor of using bool::then()

…for any ABI

The current phrasing was not very clear on that aspect.

Let `try_collect` take advantage of `try_fold` overrides

No public API changes.

With this change, `try_collect` (rust-lang#94047) is no longer going through the `impl Iterator for &mut impl Iterator`, and thus will be able to use `try_fold` overrides instead of being forced through `next` for every element.

Here's the test added, to see that it fails before this PR (once a new enough nightly is out): https://play.rust-lang.org/?version=nightly&mode=debug&edition=2021&gist=462f2896f2fed2c238ee63ca1a7e7c56

This might as well go to the same person as my last `try_process` PR  (rust-lang#93572), so
r? ``@yaahc``

…, r=petrochenkov

Always evaluate all cfg predicate in all() and any()

This pull-request adjust the handling of the `all()` and `any()` to always evaluate every cfg predicate because not doing so result in accepting incorrect `cfg`:

```rust
#[cfg(any(unix, foo::bar))] // Should error on foo::bar, but does not on unix platform (but does on non unix platform)
fn foo1() {}

#[cfg(all(foo, foo::bar))] // Should error on foo::bar, but does not
fn foo2() {}

#[cfg(all(foo::bar, foo))] // Correctly error on foo::bar
fn foo3() {}

#[cfg(any(foo::bar, foo))] // Correctly error on foo::bar
fn foo4() {}
```
This pull-request take the side to directly turn it into a hard error instead of having a future incompatibility lint because the combination to get this incorrect behavior is unusual and highly probable that some code have this without noticing.

A [search](https://cs.github.com/?scopeName=All+repos&scope=&q=lang%3Arust+%2Fany%5C%28%5Ba-zA-Z%5D%2C+%5Ba-zA-Z%5D%2B%3A%3A%5Ba-zA-Z%5D%2B%2F) on Github reveal no such instance nevertheless a Crater run should probably be done before merging this.

This was discover in rust-lang#94175 when trying to lint on the second predicate. Also note that this seems to have being introduce with Rust 1.27.0: https://rust.godbolt.org/z/KnfqKv15f.

r? `@petrochenkov`

…ion, r=Mark-Simulacrum

Compare installed browser-ui-test version to the one used in CI

I happened a few times to run into (local) rustdoc GUI tests errors because I forgot to update my browser-ui-test version. I know at least two others who encountered the same problem so I think emitting a warning to let us know about this version mismatch would make it easier to figure out.

So now, I'm not too sure that this PR is the right approach because it requires to parse a Dockerfile, which feels pretty bad. I had the idea to instead store the browser-ui-test version into a docker ARG like:

```docker
ARG BROWSER_UI_TEST_VERSION=0.8.0
```

And then use it as such in the command to make the parsing more reliable.

Or we could store this version into a file and import this file into the Dockerfile and read it from the builder.

Any preference or maybe another solution?

r? ``@Mark-Simulacrum``

…ylan-DPC

Add test for >65535 hashes in lexing raw string

…ylan-DPC

Derive Eq for std::cmp::Ordering, instead of using manual impl.

This allows consts of type Ordering to be used in patterns, and with feature(adt_const_params) allows using `Ordering` as a const generic parameter.

Currently, `std::cmp::Ordering` implements `Eq` using a manually written `impl Eq for Ordering {}`, instead of `derive(Eq)`. This means that it does not implement `StructuralEq`.

This commit removes the manually written impl, and adds `derive(Eq)` to `Ordering`, so that it will implement `StructuralEq`.

…ess, r=dtolnay

Add use of bool::then in sys/unix/process

Remove `else { None }` in favor of using `bool::then()`

…Jung

Document that `Option<extern "abi" fn>` discriminant elision applies for any ABI

The current phrasing was not very clear on that aspect.

r? `@RalfJung`

`@rustbot` modify labels: A-docs A-ffi