internal: `tracing` improvements and followups
Hi folks! Building on https://github.com/rust-lang/rust-analyzer/pull/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">
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 https://github.com/rust-lang/rust-analyzer/issues/16449
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.
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.
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](https://github.com/rust-lang/rust-analyzer/pull/16372#discussion_r1457244321) for the motivation for the new "normalize import" assist and changes to the "merge imports" assist.
