Don't treat negative trait predicates as always knowable

[compiler-errors]

We don't need this. It was added in #90104 but I don't really know why. It's not sound afaict -- negative trait predicates need the same coherence-ambiguity/orphan check rules as positive ones.

r? @lcnr

cc @spastorino, do you remember why?

[spastorino]

For the record it was added in this commit 89a419c, I don't remember exactly why but you're right.

@bors r+

[bors]

📌 Commit 808e174 has been approved by spastorino

It is now in the queue for this repository.

[bors]

⌛ Testing commit 808e174 with merge 2efa46d...

[bors]

☀️ Test successful - checks-actions
Approved by: spastorino
Pushing 2efa46d to master...

[rust-timer]

Finished benchmarking commit (2efa46d): comparison URL.

Overall result: ❌✅ regressions and improvements - 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)	0.2%	[0.2%, 0.2%]	1
Regressions ❌ (secondary)	0.3%	[0.3%, 0.4%]	3
Improvements ✅ (primary)	-0.8%	[-0.8%, -0.8%]	1
Improvements ✅ (secondary)	-29.9%	[-57.8%, -1.9%]	2
All ❌✅ (primary)	-0.3%	[-0.8%, 0.2%]	2

Max RSS (memory usage)

Results

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)	3.4%	[2.5%, 4.3%]	2
Improvements ✅ (primary)	-2.0%	[-2.0%, -2.0%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.0%	[-2.0%, -2.0%]	1

Cycles

Results

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)	-63.8%	[-63.8%, -63.8%]	1
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 652.287s -> 652.317s (0.00%)

[lcnr]

probably some weird inlining changes, but mostly positive so 🤷

or maybe it' not noise but slight changes in how we compute stuff, given that it only impacts incremental. Anyways, don't think there's anythign we should do here

[nnethercote]

A small mixture of tiny wins and losses, nothing to worry about.

@rustbot label: +perf-regression-triaged

[nnethercote]

The outsized unused-warnings check incr-unchanged improvement was just a reversion of a tiny blip first seen in #113281.