Add TyCtxt::is_lang_item, use it in the compiler

[compiler-errors]

pub fn is_lang_item(self, def_id: DefId, lang_item: LangItem) -> bool;

Easier than having to use Some(def_id) == tcx.lang_items().iterator_trait() or something. Also makes it easier to turn into TraitSolverLangItem in the future. Hope it's not too bad for perf.

r? @lcnr or @oli-obk

[compiler-errors]

@bors try @rust-timer queue

[rustbot]

Some changes occurred in match lowering

cc @Nadrieril

Some changes occurred to the core trait solver

cc @rust-lang/initiative-trait-system-refactor

Some changes occurred in compiler/rustc_codegen_cranelift

cc @bjorn3

Some changes occurred in compiler/rustc_sanitizers

cc @rust-lang/project-exploit-mitigations, @rcvalle

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[bors]

⌛ Trying commit 266754c with merge 0ad747e...

[bors]

💔 Test failed - checks-actions

[oli-obk]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 93ff86e with merge be24883...

[oli-obk]

In my ideal world we'd be able to preregister def ids like we do with symbols, so lang items can be constant def ids that we can match on (instead of having if/elseif chains), but I don't know how to get there yet in a non-hacky way.

Something like this is preferrable. If perf is an issue, maybe a macro to hide the boilerplate would work, too?

[bors]

☀️ Try build successful - checks-actions
Build commit: be24883 (be248837ad9f9bbeed1e754e9c4f4d54333323d4)

[rust-timer]

Finished benchmarking commit (be24883): comparison URL.

Overall result: ❌ regressions - ACTION NEEDED

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please fix the regressions and do another perf run. If the next run shows neutral or positive results, the label will be automatically removed.

@bors rollup=never
@rustbot label: -S-waiting-on-perf +perf-regression

Instruction count

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

	mean	range	count
Regressions ❌ (primary)	0.3%	[0.2%, 0.4%]	7
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.3%	[0.2%, 0.4%]	7

Max RSS (memory usage)

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

Cycles

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

Binary size

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

Bootstrap: 671.997s -> 672.355s (0.05%)
Artifact size: 320.43 MiB -> 319.79 MiB (-0.20%)

[compiler-errors]

That's barely anything lol

[oli-obk]

@bors r+

[bors]

📌 Commit 93ff86e has been approved by oli-obk

It is now in the queue for this repository.

[bors]

⌛ Testing commit 93ff86e with merge 8217b41...

[bors]

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing 8217b41 to master...

[rust-timer]

Finished benchmarking commit (8217b41): comparison URL.

Overall result: ❌ regressions - ACTION NEEDED

Next Steps: If you can justify the regressions found in this perf run, please indicate this with @rustbot label: +perf-regression-triaged along with sufficient written justification. If you cannot justify the regressions please open an issue or create a new PR that fixes the regressions, add a comment linking to the newly created issue or PR, and then add the perf-regression-triaged label to this PR.

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

Instruction count

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

	mean	range	count
Regressions ❌ (primary)	0.3%	[0.2%, 0.4%]	10
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.3%	[0.2%, 0.4%]	10

Max RSS (memory usage)

Results (primary -2.2%)

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

Cycles

Results (secondary 8.7%)

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)	8.7%	[7.8%, 9.3%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

Results (secondary -0.0%)

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)	-0.0%	[-0.0%, -0.0%]	1
All ❌✅ (primary)	-	-	0

Bootstrap: 671.712s -> 671.15s (-0.08%)
Artifact size: 320.45 MiB -> 319.77 MiB (-0.21%)

[rylev]

That's barely anything lol

I assume this means that the regressions that were seen aren't considered severe enough.

@rustbot label: +perf-regression-triaged