Reduce optimization level

[Mark-Simulacrum]

Mostly trying to see what the delta in build time vs. runtime performance is on our perf suite, I think it's unlikely we'd want to land this.

r? ghost

[Mark-Simulacrum]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: 27641ce (27641cefbed45ce5077076aeee68006ab17894d2, parent: 9050733395f7c10560d49f549e022f411fa28cea)

[rust-timer]

Finished benchmarking commit (27641ce): comparison URL.

Overall result: ❌ regressions - please read the text below

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please do so in sufficient writing along with @rustbot label: +perf-regression-triaged. If not, please fix the regressions and do another perf run. If its results are neutral or positive, the label will be automatically removed.

@bors rollup=never
@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)	14.8%	[0.7%, 29.9%]	269
Regressions ❌ (secondary)	16.8%	[0.6%, 52.0%]	314
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	14.8%	[0.7%, 29.9%]	269

Max RSS (memory usage)

Results (primary 3.4%, secondary 4.7%)

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

	mean	range	count
Regressions ❌ (primary)	3.4%	[0.5%, 11.5%]	131
Regressions ❌ (secondary)	4.7%	[0.6%, 11.9%]	258
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.4%	[0.5%, 11.5%]	131

Cycles

Results (primary 8.9%, secondary 12.0%)

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

	mean	range	count
Regressions ❌ (primary)	8.9%	[2.0%, 24.4%]	244
Regressions ❌ (secondary)	12.0%	[1.6%, 48.9%]	301
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	8.9%	[2.0%, 24.4%]	244

Binary size

Results (primary 0.1%, secondary 0.1%)

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

	mean	range	count
Regressions ❌ (primary)	0.1%	[0.1%, 0.1%]	4
Regressions ❌ (secondary)	0.1%	[0.1%, 0.1%]	34
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.1%	[0.1%, 0.1%]	4

Bootstrap: 473.019s -> 360.071s (-23.88%)
Artifact size: 386.89 MiB -> 456.05 MiB (17.88%)