Use unstable sorts if deduplicating (#58751)
# Impact
Recent Project picker, `find all references`, the sidebar's
`rebuild_contents` might get a slight speed boost.
# Reasoning
Unstable sort variants
https://doc.rust-lang.org/stable/std/primitive.slice.html#method.sort_unstable
are non-allocating but potentially destructive. Since we're
deduplicating elements anyways, use the unstable variant.
This call will use ipnsort
https://github.com/Voultapher/sort-research-rs/blob/main/writeup/unreasonable/text.md#various-generic-algorithms
I expect the speedups to be at least 30%, though it's highly input
dependent.
Self-Review Checklist:
- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [x] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable
Release Notes:
- N/A
Miguel Raz Guzmán Macedo
78658778a2