only next-solver: move implied bounds computation out of borrowck

[lcnr]

version of #160491 which does not enable this change for the old solver, meaning that we can merge it without a types team FCP :>

r? adwinwhite

[rustbot]

adwinwhite is currently at their maximum review capacity.
They may take a while to respond.

[adwinwhite]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: 64561ff (64561ffbe3ce67ee25e5f81cbfc58680b0b69753)
Base parent: 93c9086 (93c9086fdd5b80d286480a19ac047746ecc5fa1f)

[rust-timer]

Finished benchmarking commit (64561ff): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never rustc-perf
@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)	1.1%	[0.7%, 1.6%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.5%	[-0.6%, -0.2%]	7
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 0.4%, secondary -0.7%)

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

	mean	range	count
Regressions ❌ (primary)	1.9%	[1.9%, 1.9%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-1.0%	[-1.0%, -1.0%]	1
Improvements ✅ (secondary)	-0.7%	[-0.7%, -0.7%]	1
All ❌✅ (primary)	0.4%	[-1.0%, 1.9%]	2

Cycles

Results (primary -0.5%, secondary 2.3%)

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

	mean	range	count
Regressions ❌ (primary)	2.4%	[2.4%, 2.4%]	1
Regressions ❌ (secondary)	5.7%	[2.3%, 9.3%]	5
Improvements ✅ (primary)	-3.3%	[-3.3%, -3.3%]	1
Improvements ✅ (secondary)	-3.4%	[-4.0%, -2.5%]	3
All ❌✅ (primary)	-0.5%	[-3.3%, 2.4%]	2

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 455.615s -> 458.36s (0.60%)
Artifact size: 396.47 MiB -> 398.86 MiB (0.60%)

[adwinwhite]

This fixes a soundness hole in borrowck. Since this only affects a single crate in benchmark, we can look into it later alongside our current next‑solver perf work.
@rustbot label: +perf-regression-triaged

@bors r+

[rust-bors]

📌 Commit e77a2d7 has been approved by adwinwhite

It is now in the queue for this repository.

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[lcnr]

@bors r=adwinwhite

[rust-bors]

📌 Commit 457c9db has been approved by adwinwhite

It is now in the queue for this repository.