Remove NonOwner variant from AstOwner

[aerooneqq]

The refactoring extracted from #163495 that should be responsible for memory improvements. And seems logical that enum AstOwner should not contain variant NonOwner.

r? @petrochenkov

[aerooneqq]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: a23d5fc (a23d5fce84cb9602f797d5695f94b7951213041c)
Base parent: b57eb9a (b57eb9a5fd94f30697f51fc88fbe898e67c7aae6)

[rust-timer]

Finished benchmarking commit (a23d5fc): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never rustc-perf
@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)	0.3%	[0.3%, 0.3%]	1
Improvements ✅ (primary)	-0.7%	[-0.9%, -0.2%]	3
Improvements ✅ (secondary)	-0.2%	[-0.3%, -0.1%]	7
All ❌✅ (primary)	-0.7%	[-0.9%, -0.2%]	3

Max RSS (memory usage)

Results (primary -3.0%, 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)	-	-	0
Regressions ❌ (secondary)	2.0%	[1.6%, 2.4%]	3
Improvements ✅ (primary)	-3.0%	[-8.0%, -1.0%]	114
Improvements ✅ (secondary)	-3.1%	[-5.0%, -1.1%]	25
All ❌✅ (primary)	-3.0%	[-8.0%, -1.0%]	114

Cycles

Results (primary 2.1%, secondary 0.0%)

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

	mean	range	count
Regressions ❌ (primary)	2.1%	[2.1%, 2.1%]	1
Regressions ❌ (secondary)	3.4%	[2.3%, 4.1%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-6.7%	[-9.4%, -4.0%]	2
All ❌✅ (primary)	2.1%	[2.1%, 2.1%]	1

Binary size

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

Bootstrap: 489.693s -> 490.731s (0.21%)
Artifact size: 409.33 MiB -> 408.61 MiB (-0.18%)

[joshtriplett]

Nice! I was just starting to investigate this, and then found your PR. Thanks!

Great win on max-rss, and a slight instruction-count improvement as well.

@bors r+

[rust-bors]

📌 Commit cb35723 has been approved by joshtriplett

It is now in the queue for this repository.

[JonathanBrouwer]

@bors rollup=iffy

[rust-timer]

Note

This PR was benchmarked as part of triage of its containing rollup: triage URL.

Finished benchmarking commit (a4cb38b): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -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
Improvements ✅ (primary)	-0.6%	[-1.0%, -0.2%]	3
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	3
All ❌✅ (primary)	-0.6%	[-1.0%, -0.2%]	3

Max RSS (memory usage)

Results (primary -3.4%, secondary -2.1%)

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
Improvements ✅ (primary)	-3.4%	[-4.1%, -1.1%]	12
Improvements ✅ (secondary)	-2.1%	[-3.0%, -1.6%]	4
All ❌✅ (primary)	-3.4%	[-4.1%, -1.1%]	12

Cycles

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

Binary size

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

Artifact size: 408.60 MiB -> 408.60 MiB (-0.00%)