enable next solver by default in orphanck

[sjwang05]

• I did not use an LLM to create a change in this PR.
• I used an LLM to create a change in this PR, and I have explained below how it was used.

Orphan checking was supposed to use next solver as well when -Znext-solver=coherence got stabilized, but it never actually did, so this PR fixes that as part of the effort here: #t-types/call-for-participation > rip out old solver coherence support @ 💬

also fixes #149703, incidentally!

r? lcnr

[rustbot]

This PR changes a file inside tests/crashes. If a crash was fixed, please move into the corresponding ui subdir and add 'Fixes #' to the PR description to autoclose the issue upon merge.

[adwinwhite]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: c029389 (c029389d9a6de885e84a538a6618e9ccc532787d)
Base parent: 84b36a7 (84b36a78a28a63f134171c670be1932ffa2485f8)

[lcnr]

any breakage caused by this would also be caught by #133502. So I don't think this needs a separate crater run actually

[lcnr]

@rfcbot fcp merge types

[rust-rfcbot]

@lcnr has proposed to merge this. The next step is review by the rest of the tagged team members:

• @BoxyUwU
• @jackh726
• @lcnr
• @oli-obk
• @spastorino

No concerns currently listed.

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

[rust-rfcbot]

🔔 This is now entering its final comment period, as per the review above. 🔔

[rust-timer]

Finished benchmarking commit (c029389): comparison URL.

Overall result: ✅ improvements - no action needed

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.

@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)	-	-	0
Improvements ✅ (primary)	-0.4%	[-0.4%, -0.4%]	1
Improvements ✅ (secondary)	-0.4%	[-0.5%, -0.2%]	7
All ❌✅ (primary)	-0.4%	[-0.4%, -0.4%]	1

Max RSS (memory usage)

Results (primary -4.2%)

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)	-4.2%	[-5.8%, -2.6%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-4.2%	[-5.8%, -2.6%]	2

Cycles

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

Binary size

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

Bootstrap: 457.798s -> 459.043s (0.27%)
Artifact size: 399.35 MiB -> 398.65 MiB (-0.18%)