Create Atomic<T> type alias (rebase)

[GrigorenkoPV]

Rebase of #130543.

Additional changes:

• Switch from allow to expect for private_bounds on AtomicPrimitive
• Unhide AtomicPrimitive::AtomicInner from docs, because rustdoc shows the definition pub type Atomic<T> = <T as AtomicPrimitive>::AtomicInner; and generated links for it.
  • NonZero did not have this issue, because they kept the new alias private before the direction was changed.
• Use Atomic<_> in more places, including inside Once's Futex. This is possible thanks to declare_interior_mutable_const, borrow_interior_mutable_const: resolve <T as Trait>::AssocT projections rust-clippy#14125

The rest will either get moved back to #130543 or #130543 will be closed in favor of this instead.

---

• ACP: ACP: Generic Atomic<T> libs-team#443 (comment)
• Tracking issue: Tracking Issue for generic Atomic #130539

[rustbot]

r? @ChrisDenton

rustbot has assigned @ChrisDenton.
They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

Use r? to explicitly pick a reviewer

[rustbot]

Failed to set assignee to ghost: invalid assignee

Note: Only org members with at least the repository "read" role, users with write permissions, or people who have commented on the PR may be assigned.

[ChrisDenton]

I've removed myself from the assigned reviewer for now but feel free to assign to me again (or r? libs) when you're ready.

[bors]

☔ The latest upstream changes (presumably #136572) made this pull request unmergeable. Please resolve the merge conflicts.

[GrigorenkoPV]

@rustbot ready
r? libs

[bors]

⌛ Testing commit 18f7196 with merge 1c37905...

[bors]

💔 Test failed - checks-actions

[bors]

☔ The latest upstream changes (presumably #140127) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

☔ The latest upstream changes (presumably #140282) made this pull request unmergeable. Please resolve the merge conflicts.

[Mark-Simulacrum]

@bors r+

[bors]

📌 Commit df3dd87 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

[bors]

⌛ Testing commit df3dd87 with merge 0134651...

[bors]

☀️ Test successful - checks-actions
Approved by: Mark-Simulacrum
Pushing 0134651 to master...

[github-actions]

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing 21079f5 (parent) -> 0134651 (this PR)

Test differences

Show 1400 test diffs

1400 doctest diffs were found. These are ignored, as they are noisy.

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
    test-dashboard 0134651fb81314870903e21b1bcbdd993d75b61a --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

1. x86_64-msvc-ext2: 5635.5s -> 6995.0s (24.1%)
2. dist-x86_64-apple: 9323.5s -> 10267.2s (10.1%)
3. x86_64-msvc-2: 6685.6s -> 7361.5s (10.1%)
4. x86_64-apple-1: 9006.2s -> 8218.0s (-8.8%)
5. aarch64-gnu: 6299.6s -> 6737.8s (7.0%)
6. dist-various-2: 3464.7s -> 3235.4s (-6.6%)
7. dist-x86_64-freebsd: 4698.8s -> 4983.6s (6.1%)
8. x86_64-msvc-1: 8563.8s -> 9036.1s (5.5%)
9. x86_64-gnu: 6617.5s -> 6255.2s (-5.5%)
10. dist-apple-various: 6438.1s -> 6754.9s (4.9%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

[rust-timer]

Finished benchmarking commit (0134651): comparison URL.

Overall result: ❌✅ regressions and improvements - 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)	0.2%	[0.2%, 0.2%]	1
Regressions ❌ (secondary)	0.7%	[0.7%, 0.7%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.0%	[-2.0%, -2.0%]	1
All ❌✅ (primary)	0.2%	[0.2%, 0.2%]	1

Max RSS (memory usage)

Results (primary 0.3%, secondary 0.9%)

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)	1.2%	[0.4%, 1.6%]	4
Regressions ❌ (secondary)	1.3%	[1.1%, 1.7%]	8
Improvements ✅ (primary)	-0.5%	[-0.6%, -0.4%]	4
Improvements ✅ (secondary)	-2.6%	[-2.6%, -2.6%]	1
All ❌✅ (primary)	0.3%	[-0.6%, 1.6%]	8

Cycles

Results (primary -0.5%)

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)	-0.5%	[-0.5%, -0.5%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.5%	[-0.5%, -0.5%]	1

Binary size

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

Bootstrap: 762.113s -> 761.588s (-0.07%)
Artifact size: 365.17 MiB -> 365.21 MiB (0.01%)