Rollup of 4 pull requests

[matthiaskrgr]

Successful merges:

• Add a regression test for #39137 #102857 (Add a regression test for Derived Hash for repr(u8) enum submits 8 bytes to Hasher instead of 1 #39137)
• Improve docs for struct_lint_level function. #102953 (Improve docs for struct_lint_level function.)
• rustdoc: make the help button a link to a page #103060 (rustdoc: make the help button a link to a page)
• Clean up anchors.goml rustdoc GUI test #103115 (Clean up anchors.goml rustdoc GUI test)

Failed merges:

r? @ghost
@rustbot modify labels: rollup

Create a similar rollup

[matthiaskrgr]

@bors r+ rollup=never p=4

[bors]

📌 Commit ae717c7 has been approved by matthiaskrgr

It is now in the queue for this repository.

[bors]

⌛ Testing commit ae717c7 with merge bf286a8...

[bors]

☀️ Test successful - checks-actions
Approved by: matthiaskrgr
Pushing bf286a8 to master...

[rust-timer]

📌 Perf builds for each rolled up PR:

PR#	Perf Build Sha
#103115	9b71b16dd3c1a2779bfe7f8947977b960c815a8d
#103060	1f84454d332d9ce35d96b6ba5468ac332cbba3dc
#102953	7837a1a1f5746b50cbfce25322b6515956d4c053
#102857	c9ca55ae096171d8528fc57fd26a33ca0eff02c1

previous master: 8be3ce9056

In the case of a perf regression, run the following command for each PR you suspect might be the cause: @rust-timer build $SHA

[rust-timer]

Finished benchmarking commit (bf286a8): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean1	range	count2
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.5%	[0.5%, 0.5%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results

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.

	mean1	range	count2
Regressions ❌ (primary)	4.6%	[4.4%, 4.7%]	4
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-9.0%	[-18.0%, -2.4%]	21
Improvements ✅ (secondary)	-3.6%	[-4.0%, -3.1%]	2
All ❌✅ (primary)	-6.8%	[-18.0%, 4.7%]	25

Cycles

Results

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.

	mean1	range	count2
Regressions ❌ (primary)	2.3%	[1.2%, 3.3%]	43
Regressions ❌ (secondary)	2.9%	[2.1%, 3.7%]	23
Improvements ✅ (primary)	-14.9%	[-29.0%, -2.0%]	43
Improvements ✅ (secondary)	-8.8%	[-12.4%, -4.2%]	12
All ❌✅ (primary)	-6.3%	[-29.0%, 3.3%]	86

Footnotes

1. the arithmetic mean of the percent change ↩ ↩² ↩³

2. number of relevant changes ↩ ↩² ↩³

[Mark-Simulacrum]

Memory usage improvement seems driven by rust-lang/rustc-perf#1450 (comment) -- maybe less parallelism so less memory?