Now https://msys2.github.io/ redirects to https://www.msys2.org/, so
the README might just link to that immediately.

This essentially switches search-index.js from a "array of struct"
to a "struct of array" format, like this:

    {
    "doc": "Crate documentation",
    "t": [ 1, 1, 2, 3, ... ],
    "n": [ "Something", "SomethingElse", "whatever", "do_stuff", ... ],
    "q": [ "a::b", "", "", "", ... ],
    "d": [ "A Struct That Does Something", "Another Struct", "a function", "another function", ... ],
    "i": [ 0, 0, 1, 1, ... ],
    "f": [ null, null, [], [], ... ],
    "p": ...,
    "a": ...
    }

So `{ty: 1, name: "Something", path: "a::b", desc: "A Struct That Does Something", parent_idx: 0, search_type: null}` is the first item.

This makes the uncompressed version smaller, but it really shows on the
compressed version:

    notriddle:rust$ wc -c new-search-index1.52.0.js
    2622427 new-search-index1.52.0.js
    notriddle:rust$ wc -c old-search-index1.52.0.js
    2725046 old-search-index1.52.0.js
    notriddle:rust$ gzip new-search-index1.52.0.js
    notriddle:rust$ gzip old-search-index1.52.0.js
    notriddle:rust$ wc -c new-search-index1.52.0.js.gz
    239385 new-search-index1.52.0.js.gz
    notriddle:rust$ wc -c old-search-index1.52.0.js.gz
    296328 old-search-index1.52.0.js.gz
    notriddle:rust$

That's a 4% improvement on the uncompressed version (fewer `[]`),
and 20% improvement after gzipping it, thanks to putting like-typed
data next to each other. Any compression algorithm based on a sliding
window will probably show this kind of improvement.

…into account

These were removed in rust-lang#50198

…r=Mark-Simulacrum

Clarify what `Cell::replace` returns

…ftSpider

Rustdoc Json: Add tests for Reexports, and improve jsondocck

The two changes are orthognal, so you can land just one if you want, but the improved errors realy helped write the tests.

Notably does not have the case from rust-lang#80664, but I want to have all the ajacent cases tested before starting work on that to ensure I dont break anything.

Improves rust-lang#81359

cc ``@CraftSpider``

r? ``@jyn514``

``@rustbot`` modify labels: +A-testsuite +T-rustdoc +A-rustdoc-json

…astorino

Add `-Z unpretty` flag for the THIR

This adds a new perma-unstable flag, `-Zunpretty=thir-tree`, that dumps the raw THIR tree for each body in the crate.

Implements the THIR part of MCP rust-lang/compiler-team#408, helps with rust-lang/rustc-dev-guide#1062.
Depends on rust-lang#82495, blocked on that. Only the two last commits are added by this PR.
r? ``@spastorino`` cc ``@estebank``

…n514

convert slice doc link to intra-doc links

Continuing where rust-lang#80189 stopped, with `core::slice`.

I had an issue with two dead links in my doc when implementing `Deref<Target = [T]>` for one of my type. This means that [`binary_search_by_key`](https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.binary_search_by_key) was available, but not [`sort_by_key`](https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.sort_by_key) even though it was linked in it's doc (same issue with [`as_ptr`](https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.as_ptr) and [`as_mut_pbr`](https://doc.rust-lang.org/nightly/std/primitive.slice.html#method.as_mut_ptr)). It becomes available if I implement `DerefMut`, as it needs an `&mut self`.

<details>
  <summary>Code that will have dead links in its doc</summary>

```rust
pub struct A;
pub struct B;

impl std::ops::Deref for B{
    type Target = [A];

    fn deref(&self) -> &Self::Target {
        &A
    }
}
```
</details>

I removed the link to `sort_by_key` from `binary_search_by_key` doc as I didn't find a nice way to have a live link:
- `binary_search_by_key` is in `core`
- `sort_by_key` is in `alloc`
- intra-doc link `slice::sort_by_key` doesn't work, as `alloc` is not available when `core` is being build (the warning can't be ignored: ```error[E0710]: an unknown tool name found in scoped lint: `rustdoc::broken_intra_doc_links` ```)
- keeping the link as an anchor `#method.sort_by_key` meant a dead link
- an absolute link would work but doesn't feel right...

Add spirv extension handling in compiletest

We're trying to use `compiletest` for Rust-GPU's testsuite, and ran into an issue with host specific extensions. This adds handling to fix that.

update MSYS2 link in README

Now https://msys2.github.io/ redirects to https://www.msys2.org/, so the README might just link to that immediately.

…mo157

Fix "run" button position in error index

This isn't really a rustdoc issue but I still made the same fix in the `rustdoc.css` file (doesn't hurt).

Before:

![Screenshot from 2021-03-10 16-35-49](https://user-images.githubusercontent.com/3050060/110655807-aa402800-81bf-11eb-8a88-bc979efd1697.png)

After:

![Screenshot from 2021-03-10 16-40-08](https://user-images.githubusercontent.com/3050060/110655843-b4622680-81bf-11eb-8670-42975d92b4eb.png)

cc ```@jyn514``` (considering this is quite a big bug and an easy fix)
r? ```@Nemo157```

…Simulacrum

Ignore Vim swap files

I got this from [a Stack Overflow answer][so].
(I didn't add `*~` because it was already there.)

[so]: https://stackoverflow.com/a/4824199

…aumeGomez

rustdoc: tweak the search index format

This essentially switches search-index.js from a "array of struct" to a "struct of array" format, like this:

    {
    "doc": "Crate documentation",
    "t": [ 1, 1, 2, 3, ... ],
    "n": [ "Something", "SomethingElse", "whatever", "do_stuff", ... ],
    "q": [ "a::b", "", "", "", ... ],
    "d": [ "A Struct That Does Something", "Another Struct", "a function", "another function", ... ],
    "i": [ 0, 0, 1, 1, ... ],
    "f": [ null, null, [], [], ... ],
    "p": ...,
    "a": ...
    }

So `{ty: 1, name: "Something", path: "a::b", desc: "A Struct That Does Something", parent_idx: 0, search_type: null}` is the first item.

This makes the uncompressed version smaller, but it really shows on the compressed version:

    notriddle:rust$ wc -c new-search-index1.52.0.js
    2622427 new-search-index1.52.0.js
    notriddle:rust$ wc -c old-search-index1.52.0.js
    2725046 old-search-index1.52.0.js
    notriddle:rust$ gzip new-search-index1.52.0.js
    notriddle:rust$ gzip old-search-index1.52.0.js
    notriddle:rust$ wc -c new-search-index1.52.0.js.gz
    239385 new-search-index1.52.0.js.gz
    notriddle:rust$ wc -c old-search-index1.52.0.js.gz
    296328 old-search-index1.52.0.js.gz

That's a 4% improvement on the uncompressed version (fewer `[]`, and also changing `null` to `0` in the parent_idx list), and 20% improvement after gzipping it, thanks to putting like-typed data next to each other. Any compression algorithm based on a sliding window will probably show this kind of improvement.

Adjust some `#[cfg]`s to take non-Unix non-Windows operating systems into account

This makes compilation to such targets (e.g. `wasm32-wasi`) easier.

cc rust-lang/miri#722 rust-lang@bb6d1d0#r48100619

Reintroduce accidentally deleted assertions.

These were removed in rust-lang#50198

Update RLS

Fixes rust-lang#82932

r? ``@ghost``