Skip typeck for items w/o their own typeck context

[zetanumbers]

Skip items which forward typeck to their ancestor.

Should remove some potential but unnecessary typeck query waits, hence might improve performance for the parallel frontend.

Thanks to @ywxt for a fix suggestion

Fixes #141951

[rustbot]

r? @jieyouxu

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[ywxt]

Perhas should have a test under tests/ui/parallel-rustc.

[jieyouxu]

r? compiler

[lcnr]

@bors try @rust-timer queue

do we still use typeck for non-roots? I think we do 🤔 🤷

[rust-bors]

☀️ Try build successful (CI)
Build commit: 3da72c7 (3da72c75439245c034acfdf05ff2423fd1256d8c, parent: beeb8e3af54295ba494c250e84ecda4c2c5d85ff)

[rust-timer]

Finished benchmarking commit (3da72c7): comparison URL.

Overall result: ✅ improvements - no action needed

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.

@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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.3%	[-1.3%, -1.3%]	1
Improvements ✅ (secondary)	-1.3%	[-1.3%, -1.3%]	1
All ❌✅ (primary)	-1.3%	[-1.3%, -1.3%]	1

Max RSS (memory usage)

Results (primary 4.0%)

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

	mean	range	count
Regressions ❌ (primary)	4.0%	[3.2%, 4.7%]	2
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	4.0%	[3.2%, 4.7%]	2

Cycles

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

Binary size

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

Bootstrap: 466.876s -> 469.127s (0.48%)
Artifact size: 387.41 MiB -> 387.40 MiB (-0.00%)

[lcnr]

@bors r+

[bors]

📌 Commit 7e826fb has been approved by lcnr

It is now in the queue for this repository.