Remove QPath::LangItem

[camsteffen]

Closes #115178.

r? cjgillot

[rustbot]

HIR ty lowering was modified

cc @fmease

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

Some changes occurred in compiler/rustc_ast_lowering/src/format.rs

cc @m-ou-se

Some changes occurred in need_type_info.rs

cc @lcnr

[cjgillot]

Thanks for the very clean PR!
@bors r+

[bors]

📌 Commit 95732f4 has been approved by cjgillot

It is now in the queue for this repository.

[bors]

⌛ Testing commit 95732f4 with merge 6906167...

[bors]

☀️ Test successful - checks-actions
Approved by: cjgillot
Pushing 6906167 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 72fe2ff (parent) -> 6906167 (this PR)

Test differences

Show 80 test diffs

80 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 6906167e01fba6f702f123264653f8e401546731 --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. dist-aarch64-msvc: 6339.2s -> 5221.7s (-17.6%)
2. aarch64-apple: 8177.9s -> 9075.8s (+11.0%)
3. dist-x86_64-apple: 6805.1s -> 7544.2s (+10.9%)
4. x86_64-gnu-tools: 3440.7s -> 3783.8s (+10.0%)
5. x86_64-gnu-llvm-20-1: 3208.7s -> 3493.1s (+8.9%)
6. x86_64-rust-for-linux: 2425.9s -> 2636.5s (+8.7%)
7. dist-s390x-linux: 5222.8s -> 4793.9s (-8.2%)
8. i686-gnu-2: 5818.4s -> 6279.5s (+7.9%)
9. x86_64-gnu-aux: 6254.4s -> 6749.2s (+7.9%)
10. x86_64-msvc-2: 7139.2s -> 6580.4s (-7.8%)

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 (6906167): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Our benchmarks found a performance regression caused by this PR.
This might be an actual regression, but it can also be just noise.

Next Steps:

• If the regression was expected or you think it can be justified,
  please write a comment with sufficient written justification, and add
  @rustbot label: +perf-regression-triaged to it, to mark the regression as triaged.
• If you think that you know of a way to resolve the regression, try to create
  a new PR with a fix for the regression.
• If you do not understand the regression or you think that it is just noise,
  you can ask the @rust-lang/wg-compiler-performance working group for help (members of this group
  were already notified of this PR).

@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance

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)	1.1%	[0.2%, 2.9%]	3
Regressions ❌ (secondary)	0.4%	[0.1%, 1.3%]	21
Improvements ✅ (primary)	-0.2%	[-0.4%, -0.1%]	18
Improvements ✅ (secondary)	-0.1%	[-0.2%, -0.0%]	2
All ❌✅ (primary)	-0.0%	[-0.4%, 2.9%]	21

Max RSS (memory usage)

Results (primary 0.9%, secondary 1.5%)

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

	mean	range	count
Regressions ❌ (primary)	2.3%	[0.5%, 4.2%]	2
Regressions ❌ (secondary)	1.5%	[0.8%, 2.0%]	4
Improvements ✅ (primary)	-2.0%	[-2.0%, -2.0%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.9%	[-2.0%, 4.2%]	3

Cycles

Results (primary 3.8%, secondary 2.2%)

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

	mean	range	count
Regressions ❌ (primary)	3.8%	[3.8%, 3.8%]	1
Regressions ❌ (secondary)	2.2%	[2.2%, 2.2%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.8%	[3.8%, 3.8%]	1

Binary size

Results (primary 1.1%, 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)	1.1%	[1.1%, 1.1%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.0%	[-0.0%, -0.0%]	1
All ❌✅ (primary)	1.1%	[1.1%, 1.1%]	1

Bootstrap: 475.302s -> 475.565s (0.06%)
Artifact size: 390.18 MiB -> 390.38 MiB (0.05%)