Prepare NonNull for pattern types

[oli-obk]

Pull out the changes that affect some tests, but do not require pattern types.

See #136006 (comment) for what triggered this PR

r? @scottmcm

[oli-obk]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: ea5f33e (ea5f33ec13511047f4f28548657d6f308b541315, parent: fef627b1ebdc7369ddf8a4031a5d25733ac1fb34)

[rust-timer]

Finished benchmarking commit (ea5f33e): comparison URL.

Overall result: ❌✅ regressions and improvements - 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)	1.3%	[1.3%, 1.3%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.5%	[-0.5%, -0.5%]	1
Improvements ✅ (secondary)	-0.5%	[-0.5%, -0.5%]	2
All ❌✅ (primary)	0.4%	[-0.5%, 1.3%]	2

Max RSS (memory usage)

Results (primary -0.7%, secondary 8.5%)

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

	mean	range	count
Regressions ❌ (primary)	4.4%	[4.4%, 4.4%]	1
Regressions ❌ (secondary)	8.5%	[8.5%, 8.5%]	1
Improvements ✅ (primary)	-3.3%	[-3.8%, -2.7%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.7%	[-3.8%, 4.4%]	3

Cycles

Results (secondary 0.4%)

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)	2.9%	[2.9%, 2.9%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.2%	[-2.2%, -2.2%]	1
All ❌✅ (primary)	-	-	0

Binary size

Results (primary 0.6%)

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

	mean	range	count
Regressions ❌ (primary)	0.6%	[0.6%, 0.6%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.6%	[0.6%, 0.6%]	1

Bootstrap: 481.396s -> 480.639s (-0.16%)
Artifact size: 397.80 MiB -> 395.76 MiB (-0.51%)

[rust-bors]

☔ The latest upstream changes (presumably #148190) made this pull request unmergeable. Please resolve the merge conflicts.

[scottmcm]

This basically looks good, but did leave me with two thoughts.

I have no idea how important the !align metadata is. Might be ok to just file a follow-up bug to bring it back? Dunno how hard it would be to restore.

View changes since this review

[scottmcm]

up to you: if this is going to transmute anyway, maybe just transmute directly to NonNull?

Going through the usize then the pointer then the aggregate doesn't seem particularly meaningful; maybe just go straight NonZero→NonNull if there needs to be a transmute here regardless?

[scottmcm]

Hmm, if this is showing up here with just the nonnull change it looks like whatever emits this !align needs an update to see through pattern types, maybe?