Don't ICE on placeholder consts in deep reject

[compiler-errors]

Since we canonicalize const params into placeholder consts, we need to be able to handle them during deep reject.

r? @lcnr (though maybe @oli-obk can look at this one too, if he wants 😸)

Fixes compiler-errors/next-solver-hir-issues#10

[lcnr]

weird that we allow ty::Bound but not ConstKind::Bound 🤷 both should be unreachable (or well, reachable with ty/const binders)

[lcnr]

iirc this code is stupidly hot, so even if trivial, a bit worried this changes perf

@bors try @rust-timer queue

r=me afterwards

[bors]

⌛ Trying commit 1ce6e2b with merge d439f8967e8c9de02557632b30e15cca99fdb8c5...

[bors]

☀️ Try build successful - checks-actions
Build commit: d439f8967e8c9de02557632b30e15cca99fdb8c5 (d439f8967e8c9de02557632b30e15cca99fdb8c5)

[rust-timer]

Finished benchmarking commit (d439f8967e8c9de02557632b30e15cca99fdb8c5): comparison URL.

Overall result: ✅ improvements - no 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.

@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
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.2%	[-0.3%, -0.2%]	2
All ❌✅ (primary)	-	-	0

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)	2.9%	[2.4%, 3.4%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

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)	-2.1%	[-2.1%, -2.1%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.1%	[-2.1%, -2.1%]	1

[lcnr]

@bors r+

[bors]

📌 Commit 1ce6e2b has been approved by lcnr

It is now in the queue for this repository.

[bors]

⌛ Testing commit 1ce6e2b with merge ec2f40c...

[bors]

☀️ Test successful - checks-actions
Approved by: lcnr
Pushing ec2f40c to master...

[rust-timer]

Finished benchmarking commit (ec2f40c): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

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

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)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.5%	[-1.5%, -1.5%]	1
All ❌✅ (primary)	-	-	0

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)	2.8%	[2.8%, 2.8%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	2.8%	[2.8%, 2.8%]	1