collapse constness query match logic

[fee1-dead]

We already have the HIR node data, so no need for asking def_kind again.

r? oli-obk

[rustbot]

Some changes occurred to the CTFE machinery

cc @RalfJung, @oli-obk, @lcnr

[rustbot]

oli-obk is not on the review rotation at the moment.
They may take a while to respond.

[fee1-dead]

@bors try @rust-timer queue

[rust-log-analyzer]

The job x86_64-gnu-gcc failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

test [crashes] tests/crashes/136666.rs ... ok
test [crashes] tests/crashes/136661.rs ... ok
test [crashes] tests/crashes/136859.rs ... ok
test [crashes] tests/crashes/136766.rs ... ok
2025-11-29T04:47:46.366824Z ERROR compiletest::runtest: fatal error, panic: "crashtest no longer crashes/triggers ICE, hooray! Please give it a meaningful name, add a doc-comment to the start of the test explaining why it exists and move it to tests/ui or wherever you see fit. Adding 'Fixes #<issueNr>' to your PR description ensures that the corresponding ticket is auto-closed upon merge. If you want to see verbose output, set `COMPILETEST_VERBOSE_CRASHES=1`."
test [crashes] tests/crashes/137049.rs ... ok
test [crashes] tests/crashes/137187.rs ... FAILED
test [crashes] tests/crashes/137084.rs ... ok
test [crashes] tests/crashes/137190-2.rs ... ok
test [crashes] tests/crashes/137260.rs ... ok
---

---- [crashes] tests/crashes/137187.rs stdout ----
------rustc stdout------------------------------

------rustc stderr------------------------------
error[E0379]: functions in traits cannot be declared const
##[error] --> /checkout/tests/crashes/137187.rs:6:5
  |
6 |     const fn b(c: *const Self) -> <*const Self as Add>::Output {
  |     ^^^^^-
  |     |
  |     functions in traits cannot be const
  |     help: remove the `const`

---
For more information about an error, try `rustc --explain E0379`.

------------------------------------------

error: crashtest no longer crashes/triggers ICE, hooray! Please give it a meaningful name, add a doc-comment to the start of the test explaining why it exists and move it to tests/ui or wherever you see fit. Adding 'Fixes #<issueNr>' to your PR description ensures that the corresponding ticket is auto-closed upon merge. If you want to see verbose output, set `COMPILETEST_VERBOSE_CRASHES=1`.

thread '[crashes] tests/crashes/137187.rs' panicked at src/tools/compiletest/src/runtest/crashes.rs:17:18:
fatal error
stack backtrace:
   5: __rustc::rust_begin_unwind

For more information how to resolve CI failures of this job, visit this link.

[rust-bors]

☀️ Try build successful (CI)
Build commit: be2e6bc (be2e6bce7652ec2e3613195122bb1b55471268d1, parent: 1eb0657f78777f0b4d6bcc49c126d5d35212cae5)

[rust-timer]

Finished benchmarking commit (be2e6bc): comparison URL.

Overall result: no relevant changes - 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

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

Max RSS (memory usage)

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

Cycles

Results (primary -2.5%)

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)	-2.5%	[-2.5%, -2.5%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.5%	[-2.5%, -2.5%]	1

Binary size

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

Bootstrap: 472.886s -> 471.592s (-0.27%)
Artifact size: 386.93 MiB -> 386.92 MiB (-0.00%)