According to the Cargo Reference:
https://doc.rust-lang.org/cargo/reference/manifest.html

> This is an SPDX 2.1 license expression for this package. Currently
> crates.io will validate the license provided against a whitelist of
> known license and exception identifiers from the SPDX license list
> 2.4. Parentheses are not currently supported.
>
> Multiple licenses can be separated with a `/`, although that usage
> is deprecated. Instead, use a license expression with AND and OR
> operators to get more explicit semantics.

Updated to handle these changes:
  - `core::ptr::*` lost their `__0` elements and are just plain pointers
  - `core::ptr::*` probably shouldn't dereference in `DisplayString` s
  - `VecDeque` and `Vec` use `core::ptr::*` s
  - `VecDeque` and `LinkedList` moved modules again.

Retested - still working fine, left alone:
  - `String`, `&str`, `Option`

- Change wording of suggestion
- Move recovery logic to `diagnostics.rs`
- Reduce ammount of code duplication

* `HashSet::get_or_insert`
* `HashSet::get_or_insert_with`

These provide a simplification of the `Entry` API for `HashSet`, with
names chosen to match the similar methods on `Option`.

Switch to SPDX 2.1 license expression

[According to the Cargo Reference:](https://doc.rust-lang.org/cargo/reference/manifest.html)

> This is an SPDX 2.1 license expression for this package. Currently crates.io will validate the license provided against a whitelist of known license and exception identifiers from the SPDX license list 2.4. Parentheses are not currently supported.
>
> Multiple licenses can be separated with a \`/\`, although that usage is deprecated. Instead, use a license expression with AND and OR operators to get more explicit semantics.

The notation with slashes is deprecated in favor of explicit AND or OR.

As I understand it, Rust's license is MIT *OR* Apache-2.0 matching the meaning of *OR* defined by [SPDX Specification 2.1](https://spdx.org/spdx-specification-21-web-version):

> If presented with a choice between two or more licenses, use the disjunctive binary "OR" operator to construct a new license expression, where both the left and right operands are valid license expression values.

…r=alexcrichton

Fix .natvis visualizers.

### Updated to handle these changes:
  - `core::ptr::*` lost their `__0` elements and are just plain pointers
  - `core::ptr::*` probably shouldn't dereference in `DisplayString` s
  - `VecDeque` probably *should* dereference it's buf pointer to display individual items.
  - `VecDeque` and `Vec` use `core::ptr::*` s
  - `VecDeque` and `LinkedList` moved modules again.

### Retested - still working fine, left alone:
  - `String`, `&str`, `Option`

### Side Chatter
  - Props to Alex for pointing out this was broken in the `#ides-and-editors` Discord channel
  - It'd be nice if there was a sane way to automate unit testing these visualizers.
    (I assume COM automation of Visual Studio would be a no go on the build servers, and probably really incredibly painful to write too!  Suggestions welcome...)

remove compiletest's dependency on `filetime`

… r=oli-obk

Get ty from local_decls instead of using Place

r? @oli-obk This is from one of your review on Place 2.0

Parse alternative incorrect uses of await and recover

Fix rust-lang#60613.

r? @Centril

…Centril

Add entry-like methods to HashSet

* `HashSet::get_or_insert`
* `HashSet::get_or_insert_with`

These provide a simplification of the `Entry` API for `HashSet`, with
names chosen to match the similar methods on `Option`.