…oc-link-summary, r=CraftSpider

Resolve intra-doc links in summary desc

Before:

![rustdoc-intra-doc-link-summary-before](https://user-images.githubusercontent.com/1593513/122623069-9d995e80-d04f-11eb-8d46-ec2ec126bb5e.png)

After:

![rustdoc-intra-doc-link-summary](https://user-images.githubusercontent.com/1593513/122623076-a4c06c80-d04f-11eb-967a-f5916871c34b.png)

…oc-link-summary, r=CraftSpider

Resolve intra-doc links in summary desc

Before:

![rustdoc-intra-doc-link-summary-before](https://user-images.githubusercontent.com/1593513/122623069-9d995e80-d04f-11eb-8d46-ec2ec126bb5e.png)

After:

![rustdoc-intra-doc-link-summary](https://user-images.githubusercontent.com/1593513/122623076-a4c06c80-d04f-11eb-967a-f5916871c34b.png)

Rollup of 6 pull requests

Successful merges:

 - rust-lang#86393 (Add regression test for issue rust-lang#52025)
 - rust-lang#86402 (rustdoc: add optional woff2 versions of Source Serif and Source Code)
 - rust-lang#86451 (Resolve intra-doc links in summary desc)
 - rust-lang#86501 (Cleanup handling of `crate_name` for doctests)
 - rust-lang#86517 (Fix `unused_unsafe` around `await`)
 - rust-lang#86537 (Mark some edition tests as check-pass)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

It was accidentally changed to use `opts()` in rust-lang#86451.

I also renamed `opts()` to `main_body_opts()` to make this kind of
accidental change less likely.

Similar to rust-lang#86451

CC rust-lang#67799

…-resolve, r=GuillaumeGomez

rustdoc: resolve intra-doc links when checking HTML

Similar to rust-lang#86451

CC rust-lang#67799

Given this test case:

```rust
#![warn(rustdoc::invalid_html_tags)]
#![warn(rustdoc::broken_intra_doc_links)]

pub struct ExistentStruct<T>(T);

/// This [test][ExistentStruct<i32>] thing!
pub struct NoError;
```

This pull request silences the following, spurious warning:

```text
warning: unclosed HTML tag `i32`
 --> test.rs:6:31
  |
6 | /// This [test][ExistentStruct<i32>] thing!
  |                               ^^^^^
  |
note: the lint level is defined here
 --> test.rs:1:9
  |
1 | #![warn(rustdoc::invalid_html_tags)]
  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^
help: try marking as source code
  |
6 | /// This [test][`ExistentStruct<i32>`] thing!
  |                                      

warning: 1 warning emitted
```

…-meta-description, r=camelid,GuillaumeGomez

rustdoc: account for intra-doc links in `<meta name="description">`

Similar to rust-lang#86451, but for the SEO descriptions instead of the search descriptions.

…-meta-description, r=camelid,GuillaumeGomez

rustdoc: account for intra-doc links in `<meta name="description">`

Similar to rust-lang#86451, but for the SEO descriptions instead of the search descriptions.