Wrap Terminator::attributes in Option

[panstromek]

Empty ThinVec is slightly more expensive than None, because it's a pointer to a static singleton, while None is just a constant on a stack. We've seen this before in other places. This is a small win in local Cachegrind runs.

[panstromek]

@bors try @rust-timer queue

[rust-log-analyzer]

The job aarch64-gnu-llvm-21-2 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

[rust-bors]

☀️ Try build successful (CI)
Build commit: 9e7c5f7 (9e7c5f79a424c7ed70419eacd9c74d6d09ac6a7d)
Base parent: 67854e5 (67854e511de21d881bb16426996cd4259d44aa2e)

[rust-timer]

Finished benchmarking commit (9e7c5f7): comparison URL.

Overall result: ❌ regressions - no action needed

Benchmarking means the PR may be perf-sensitive. Consider adding rollup=never if this change is not fit for rolling up.

@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.6%	[0.5%, 0.7%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary -3.9%, secondary 0.8%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.8%	[0.8%, 0.8%]	1
Improvements ✅ (primary)	-3.9%	[-3.9%, -3.9%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-3.9%	[-3.9%, -3.9%]	1

Cycles

Results (primary 2.1%, secondary 2.5%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.1%	[1.7%, 2.5%]	2
Regressions ❌ (secondary)	5.9%	[1.8%, 9.6%]	5
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.2%	[-5.0%, -2.3%]	3
All ❌✅ (primary)	2.1%	[1.7%, 2.5%]	2

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 459.382s -> 458.457s (-0.20%)
Artifact size: 396.87 MiB -> 398.79 MiB (0.49%)

[panstromek]

Results are mostly below significance treshold, but they are largely positive (most benchmarks improved, so it's probably not a wash). include-blob is likely noise again.