This moves the stable sort implementation to the core::slice::sort module. By
virtue of being in core it can't access `Vec`. The two `Vec` used by merge sort,
`buf` and `runs`, are modelled as custom types that implement the very limited
required `Vec` interface with the help of provided allocation and free
functions. This is done to allow future re-use of functions and logic between
stable and unstable sort. Such as `insert_head`.

There were several unsafe blocks in the existing implementation that
were not documented with a SAFETY comment.

Since the current sidebar item is already a link, it doesn't
do anything.

paramters -> parameters

This uses less code to lay them out the same way.

Fixes rust-lang#99695

…ings_with_variant_name, r=scottmcm

Change `bindings_with_variant_name` to deny-by-default

Changed the `bindings_with_variant_name` lint to deny-by-default and fixed up the affected tests.

Addresses rust-lang#103442.

…rom-self-fixup, r=TaKO8Ki

diagnostics: suggest changing `s@self::{macro}@::macro` for exported

Fixes rust-lang#99695

…homcc

Unify stable and unstable sort implementations in same core module

This moves the stable sort implementation to the core::slice::sort module. By virtue of being in core it can't access `Vec`. The two `Vec` used by merge sort, `buf` and `runs`, are modelled as custom types that implement the very limited required `Vec` interface with the help of provided allocation and free functions. This is done to allow future re-use of functions and logic between stable and unstable sort. Such as `insert_head`.

This is in preparation of rust-lang#100856 and rust-lang#104116. It only moves code, it *doesn't* change any of the sort related logic. This unlocks the ability to share `insert_head`, `insert_tail`, `swap_if_less` `merge` and more.

Tagging ````@Mark-Simulacrum```` I hope this allows progress on rust-lang#100856, by moving `merge_sort` here I hope future changes will be easier to review.

…=albertlarsan68

check for x version updates

This PR adds a check to tidy to assert that the installed version of `x` is equal to the version in `src/tools/x/Cargo.toml`. It checks the installed version of `x` by parsing the output of `cargo install --list` (as an option proposed in this [issue](rust-lang#106469)).

It does not warn if `x` has not yet been installed, on the assumption that the user isn't interested in using it.

…didates-3, r=lcnr

Implement some more new solver candidates and fix some bugs

First, fix some bugs:

1. `IndexVec::drain_enumerated(a..b)` does not give us an iterator of index keys + items enumerated from `a..b`, but from `0..(b-a)`... That caused a bug. See first commit for the fix.
2. Implement the `_: Trait` ambiguity hack. I put it in assemble, let me know if it should live elsewhere. This is important, since we otherwise consider `_: Sized` to have no solutions, and nothing passes!
3. Swap `Ambiguity` and `Unimplemented` cases for the new solver. Sorry for accidentally swapping them 😄
4. Check GATs' own predicates during projection confirmation.

Then implement a few builtin traits:

5. Implement `PointerSized`. Pretty independent.
6. Implement `Fn` family of traits for fnptr, fndef, and closures. Closures are currently broken because `FulfillCtxt::relationships` is intentionally left unimplemented. See comment in the test.

r? ```@lcnr```

…t, r=GuillaumeGomez

rustdoc: remove redundant CSS selector `.sidebar .current`

Since the current sidebar item is already a link, it doesn't do anything.

Fix typo in opaque_types.rs

paramters -> parameters

… r=albertlarsan68

fix check macro expansion

If the only argument to `check!` is the module name I get this error:

```
error: expected expression, found `,`
   --> src/tools/tidy/src/main.rs:63:42
    |
57  | /         macro_rules! check {
58  | |             ($p:ident $(, $args:expr)* ) => {
59  | |                 drain_handles(&mut handles);
60  | |
...   |
63  | |                     $p::check($($args),* , &mut flag);
    | |                                          ^ expected expression
...   |
69  | |             }
70  | |         }
    | |_________- in this expansion of `check!`
...
117 |           check!(hey);
    |           ----------- in this macro invocation
```

This change makes it so commas are added only when there are `args`.

r? ```@albertlarsan68```

…display-inline-flex, r=GuillaumeGomez

rustdoc: use CSS inline layout for radio line instead of flexbox

This uses less code to lay them out the same way. Already tested here:

https://github.com/rust-lang/rust/blob/5ce39f42bd2c8bca9c570f0560ebe1fce4eddb14/tests/rustdoc-gui/settings.goml#L123