Rollup of 6 pull requests

[matthiaskrgr]

Successful merges:

• Ergonomic ref counting #134797 (Ergonomic ref counting)
• Clean up various LLVM FFI things in codegen_llvm #137549 (Clean up various LLVM FFI things in codegen_llvm)
• Reduce kw::Empty usage, part 1 #137977 (Reduce kw::Empty usage, part 1)
• Suggest struct or union to add generic that impls trait #138042 (Suggest struct or union to add generic that impls trait)
• tests: fix some typos in comment #138141 (tests: fix some typos in comment)
• Streamline HIR intravisit visit_id calls for items #138150 (Streamline HIR intravisit visit_id calls for items)

r? @ghost
@rustbot modify labels: rollup

Create a similar rollup

[matthiaskrgr]

@bors r+ rollup=never p=5

[bors]

📌 Commit b772fa6 has been approved by matthiaskrgr

It is now in the queue for this repository.

[bors]

⌛ Testing commit b772fa6 with merge f5a1ef7...

[bors]

☀️ Test successful - checks-actions
Approved by: matthiaskrgr
Pushing f5a1ef7 to master...

[rust-timer]

📌 Perf builds for each rolled up PR:

PR#	Message	Perf Build Sha
#134797	Ergonomic ref counting	5cf660233fcc08fce21f8845d36982b25cb0535c (link)
#137549	Clean up various LLVM FFI things in codegen_llvm	16414e51165f3551babcedf88865b96ab527ad10 (link)
#137977	Reduce kw::Empty usage, part 1	0b6c069b8fb3e54f454e85c8c5823093fa6546a7 (link)
#138042	Suggest struct or union to add generic that impls trait	aa349152c7692ec700b45826c6e36fa36667c814 (link)
#138141	tests: fix some typos in comment	275aad337ae6cfdd26e723c7bd921a8d10c565b7 (link)
#138150	Streamline HIR intravisit visit_id calls for items	eaf9440205bcce1e90324507989b942861d56cac (link)

previous master: c53af1ccd0

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 (f5a1ef7): 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
Regressions ❌ (secondary)	0.2%	[0.2%, 0.2%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 2.5%, secondary 0.8%)

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)	2.5%	[2.5%, 2.5%]	1
Regressions ❌ (secondary)	2.2%	[1.7%, 2.8%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-4.5%	[-4.5%, -4.5%]	1
All ❌✅ (primary)	2.5%	[2.5%, 2.5%]	1

Cycles

Results (secondary -2.4%)

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
Improvements ✅ (secondary)	-2.4%	[-3.9%, -1.9%]	5
All ❌✅ (primary)	-	-	0

Binary size

Results (primary 0.1%, secondary 0.1%)

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)	0.1%	[0.0%, 0.2%]	72
Regressions ❌ (secondary)	0.1%	[0.0%, 0.2%]	28
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.1%	[0.0%, 0.2%]	72

Bootstrap: 765.734s -> 766.525s (0.10%)
Artifact size: 362.10 MiB -> 362.15 MiB (0.01%)