Add completions to show only traits in trait `impl` statement
This is prerequisite PR for adding the assist mentioned in #12500
P.S: If wanted, I will add the implementation of the assist in this PR as well.
Abstract more over ItemTreeLoc-like structs
Allows reducing some code duplication by using functions generic over said structs. The diff isn't negative due to me adding some additional impls for completeness.
internal: even more `tracing`
As part of profiling completions, I added some additional spans and moved `TyBuilder::subst_for_def` closer to its usage site (the latter had a small impact on completion performance. Thanks for the tip, Lukas!)
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.
fix: add error recovery for use_tree_list parsing
This PR adds error recovery for USE_TREE_LIST parsing, avoid the wrong USE_TREE_LIST making the rest parsing incorrectly.
before
after
close https://github.com/rust-lang/rust-analyzer/issues/16227
