Add Config::hash_untracked_state callback

[Alexendoo]

For context, I'm looking to use late module passes in Clippy which unlike regular late passes run incrementally per module

However we have a config file which can change between runs, we need changes to that to invalidate the lint_mod query. This PR adds a side channel for us to hash some extra state into Options in order to do that

This does not make any changes to Clippy, I plan to do that in a PR to the Clippy repo along with some other required changes

An alternative implementation would be to add a new query to track this state and override the lint_mod query in Clippy to first call that

cc @rust-lang/clippy

[rustbot]

r? @oli-obk

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[oli-obk]

There's probably a way to design this more in line with the query system, but we can always redesign later. For now this seems really useful for drivers in general

@bors r+

[bors]

📌 Commit 59f6f04 has been approved by oli-obk

It is now in the queue for this repository.

[bors]

⌛ Testing commit 59f6f04 with merge 4af886f...

[bors]

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing 4af886f to master...

[rust-timer]

Finished benchmarking commit (4af886f): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

This benchmark run did not return any relevant results for this metric.

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.2%	[2.2%, 2.2%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 626.363s -> 627.067s (0.11%)
Artifact size: 305.53 MiB -> 305.59 MiB (0.02%)