The `CString` handling code is erroneously identical to the `ByteString`
handling code.

- Rename it as `MixedUnit`, because it will soon be used in more than
  just C string literals.
- Change the `Byte` variant to `HighByte` and use it only for
  `\x80`..`\xff` cases. This fixes the old inexactness where ASCII chars
  could be encoded with either `Byte` or `Char`.
- Add useful comments.
- Remove `is_ascii`, in favour of `u8::is_ascii`.

`unescape_literal` becomes `unescape_unicode`, and `unescape_c_string`
becomes `unescape_mixed`. Because rfc3349 will mean that C string
literals will no longer be the only mixed utf8 literals.

… macro

…ested use tree selections

…sted use tree selections

…m-ra

Add postfix completion for let else

Adds a postfix completion for let else syntax, similar to the if let postfix.

feat: Support for GOTO def from *inside* files included with include! macro

close rust-lang#14937
Try to implement goto def from *inside* files included with include! macro.
This implementation has two limitations:
1. Only **one** file which calls include! will be tracked. (I think multiple file be included is a rare case and we may let it go for now)
2. Mapping token from included file to macro call file (semantics.rs:646~658) works fine but I am not sure is this the correct way to implement.

intenral: Cleanup error variants in MIR code a bit

We configure that in the lint table in `Cargo.toml`.

internal: Add `clippy` to CI

Follow-up to rust-lang#16401

…Veykril

feat: "Normalize import" assist and utilities for normalizing use trees

- Add import/use tree normalization utilities
- Add "normalize import" assist
- Update "merge imports" assist to always apply to the covering use item except for nested use tree selections
- Update "merge imports" assist to avoid adding unnecessary braces when merging nested use tree selections

See [this discussion](rust-lang/rust-analyzer#16372 (comment)) for the motivation for the new "normalize import" assist and changes to the "merge imports" assist.

This commit also adds `tracing` to NotificationDispatcher/RequestDispatcher,
bumps `rust-analyzer-salsa` to 0.17.0-pre.6, `always-assert` to 0.2, and
removes the homegrown `hprof` implementation in favor of a vendored
tracing-span-tree.

…ans, r=Veykril

internal: add some `tracing` to {Request, Notification}Dispatch

Some of the tracing config would need to be changed in order to benefit more from this (especially `.with_span_events(FmtSpan::CLOSE)`), which provides span events like the following:

```
2024-01-18T02:41:06.675779Z  INFO request{method="textDocument/codeLens" request_id=RequestId(I32(17))}: rust_analyzer::dispatch: close time.busy=61.8µs time.idle=5.29µs
```

I dunno if y'all need `LoggerFormatter` in here, but if you don't, I'd be happy to yeet it out of rust-analyzer. In any case, this provided a pretty decent amount of information in the logs, and I can expand this as needed or we can land this PR and expand later.

…e config

internal: Undo special bracket classification for attributes in vscode config

I changed this thinking the `#` could be considered part of the bracket but on second though I don't think that's quite right in general.

Fixes rust-lang/rust-analyzer#16449

…kril

feat: enable excluding refs search results in test

## Change

Here I introduce a new `ReferenceCategory::Test` type to indicate whether the function where this reference is located is marked as `#[test]`, and expose an config item (`rust-analyzer.references.excludeTests`) to client.

I also changed the signature of `ReferenceCategory::new`, adding a `sema: &Semantics<'_, RootDatabase>` param to do some hir analysis. Hope the current implementation is good to go.

## Demo

`"rust-analyzer.references.excludeTests": false`

![include](https://github.com/rust-lang/rust-analyzer/assets/71162630/9f1176d4-7b41-4f49-ac79-55d25a42d5d1)

`"rust-analyzer.references.excludeTests": true`

![exclude](https://github.com/rust-lang/rust-analyzer/assets/71162630/2938b44b-9e5b-48de-a049-453f5bbc09d0)

close rust-lang/rust-analyzer#14530

internal: Use improved adjusted_display_range for all diagnostics

internal: Remove unnecessary usages of ExpansionInfo

And some follow up simplifications to rust-lang/rust-analyzer#16439

internal: Bump scip

Fixes rust-lang#16440

minor: correct typos

I use [crate-ci/typos](https://github.com/crate-ci/typos) to check typos in codebase, if it's ok with you, I'd like to add a typo check CI using [typos](https://github.com/crate-ci/typos) (with Apache-2.0, MIT licenses).

BTW, we can add a [_typos.toml](https://github.com/crate-ci/typos/blob/master/docs/reference.md) as white list for some intentional typos

…r=Veykril

internal: `tracing` improvements and followups

Hi folks! Building on rust-lang/rust-analyzer#16394, I've got a few small tweaks:
- Removed the accidental `mod.rs` usage that I introduced.
- Removed a panic in `pat_analysis.rs`.
- Recorded the event kind in `handle_event` to better distinguish what _kind_ of event is being handled.
- Did a small refactor of `hprof` to have somewhat more linear control flow, and more importantly, write the recorded fields to the output.

The end result is the following:
<img width="1530" alt="A screenshot of Visual Studio Code on a Mac. `hprof.rs` is open, with " src="https://github.com/rust-lang/rust-analyzer/assets/2067774/bd11dde5-b2da-4774-bc38-bcb4772d1192">

…=lnicola

internal: Remove `abi_amdgpu_kernel` references

This feature was removed in rust-lang#120495

minor: Remove `stdx::eprintln` overwrite

…=lnicola

minor: Recommend maintained Neovim plugin in documentation

internal: VS Code: report conflict with `panicbit.cargo`

<img width="359" alt="notification" src="https://github.com/rust-lang/rust-analyzer/assets/71162630/420b9f34-ba73-4436-b868-6cd87c62287d">

related to rust-lang/rust-analyzer#16392

internal: Work through temporarily allowed clippy lints, part 2

Another follow-up to rust-lang/rust-analyzer#16401.

internal: sync from downstream

internal: add typos check CI (part 2)

follow up rust-lang/rust-analyzer#16448

internal: Bump release runners to MacOS 12

…m-ra

…erialization order