Stabilize style_edition = "2024" in-tree

[compiler-errors]

This PR stabilizes the style_edition flag in rustfmt.

Why am I doing this in-tree? The beta release cut is imminent (according to forge, on January 3) and this is the most lightweight approach to getting this flag stable on nightly. It's imperative (as far as I can tell -- @traviscross can verify or disagree) that we stabilize the style_edition flag so that users can control their style edition separately from the edition.

I'm happy to move this PR to the rustfmt repo and subsequently prepare a subtree sync if someone on @rust-lang/rustfmt believes that we should get this landed on the rustfmt side then synced. If this is the right recourse, I'd like to note that this is still quite time-sensitive. However, I'm happy to dedicate time to get this done if necessary, since I'd really like to un-jeopardize the style edition.

Tracking:

• Tracking Issue for Rust 2024: rustfmt style editions #123799

[rustbot]

Some changes occurred in src/tools/rustfmt

cc @rust-lang/rustfmt

[ytmimi]

I'm happy to stabilize this in-tree.

[compiler-errors]

Ok, I'll go ahead and approve this for @ytmimi.

If @calebcartwright disagrees with this approach, then sorry for jumping the gun and I'm happy to help out with other solutions. We still have plenty of time (~6 weeks, i.e. all throughout beta) to revert this and go with some other stabilization approach. We should just be mindful that that'll need to do this work on the beta branch :)

@bors r=ytmimi

[bors]

📌 Commit f694db1 has been approved by ytmimi

It is now in the queue for this repository.

[bors]

⌛ Testing commit f694db1 with merge 80f5a81df9bdb6e11595b0ac8c0bc843786d926b...

[bors]

☀️ Test successful - checks-actions
Approved by: ytmimi
Pushing 80f5a81 to master...

[rust-timer]

Finished benchmarking commit (80f5a81): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.4%	[0.4%, 0.4%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (secondary 6.1%)

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)	6.1%	[6.1%, 6.1%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Cycles

Results (secondary -2.9%)

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)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.9%	[-2.9%, -2.9%]	1
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 761.022s -> 760.209s (-0.11%)
Artifact size: 325.49 MiB -> 325.50 MiB (0.00%)