emit ConstEquate in TypeRelating<D>

[BoxyUwU]

emitting ConstEquate during mir typeck is useful since it can help catch bugs in hir typeck incase our impl of ConstEquate is wrong.

doing this did actually catch a bug, when relating Expr::Call we == the types of all the argument consts which spuriously returns false if the type contains const projections/aliases which causes us to fall through to the expected_found error arm.
Generally its an ICE if the Const's Tys arent equal but ConstKind::Expr is kind of special since they are sort of like const items that are const CALL<F: const Fn(...), const N: F> though we dont actually explicitly represent the F type param explicitly in Expr::Call so I just made us relate the Const's ty field to avoid getting ICEs from the tests I added and the following existing test:

// tests/ui/const-generics/generic_const_exprs/different-fn.rs
#![feature(generic_const_exprs)]
#![allow(incomplete_features)]

use std::mem::size_of;
use std::marker::PhantomData;

struct Foo<T>(PhantomData<T>);

fn test<T>() -> [u8; size_of::<T>()] {
    [0; size_of::<Foo<T>>()]
    //~^ ERROR unconstrained generic constant
    //~| ERROR mismatched types
}

fn main() {
    test::<u32>();
}

which has us relate two ConstKind::Value one for the fn item of size_of::<Foo<T>> and one for the fn item of size_of::<T>(), these only differ by their Ty and if we don't relate the Ty we'll end up getting an ICE from the checks that ensure the ty fields always match.

In theory Expr::UnOp has the same problem so I added a call to relate for the ty's, although I was unable to create a repro test.

[rustbot]

r? @lcnr

(rustbot has picked a reviewer for you, use r? to override)

[BoxyUwU]

r? compiler-contributors

[compiler-errors]

r? @compiler-errors @bors r+

yeet

[bors]

📌 Commit f2c24afe0fd510f8c592e737a5c06a42c6109ca1 has been approved by compiler-errors

It is now in the queue for this repository.

[bors]

⌛ Testing commit f2c24afe0fd510f8c592e737a5c06a42c6109ca1 with merge 90c1e6c689773c8d55031328f01ca276da9d157d...

[bors]

💔 Test failed - checks-actions

[compiler-errors]

@bors retry spurious

[bors]

⌛ Testing commit f2c24afe0fd510f8c592e737a5c06a42c6109ca1 with merge c907399ed72f3a206817be8ac1085d06741f7c78...

[bors]

💔 Test failed - checks-actions

[BoxyUwU]

@bors retry

[BoxyUwU]

@bors r=compiler-errors

[bors]

💡 This pull request was already approved, no need to approve it again.

• This pull request previously failed. You should add more commits to fix the bug, or use retry to trigger a build again.
• There's another pull request that is currently being tested, blocking this pull request: Do not deaggregate MIR #107267

[bors]

📌 Commit f2c24afe0fd510f8c592e737a5c06a42c6109ca1 has been approved by compiler-errors

It is now in the queue for this repository.

[BoxyUwU]

@bors retry

[bors]

⌛ Testing commit f2c24afe0fd510f8c592e737a5c06a42c6109ca1 with merge 6ebe0f75c272d590ed38cbb30d1cde018f65c95b...

[bors]

💔 Test failed - checks-actions

[BoxyUwU]

@bors r=compiler-errors

maybe rebasing will fix everything magically

[bors]

📌 Commit d85d906 has been approved by compiler-errors

It is now in the queue for this repository.

[bors]

⌛ Testing commit d85d906 with merge 2a6ff72...

[bors]

☀️ Test successful - checks-actions
Approved by: compiler-errors
Pushing 2a6ff72 to master...

[rust-timer]

Finished benchmarking commit (2a6ff72): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -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)	-0.4%	[-0.4%, -0.3%]	2
Improvements ✅ (secondary)	-0.8%	[-1.3%, -0.2%]	10
All ❌✅ (primary)	-0.4%	[-0.4%, -0.3%]	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)	2.6%	[2.0%, 2.8%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.1%	[-2.3%, -1.7%]	3
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)	2.4%	[2.4%, 2.4%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

[michael-swan]

This introduces an ICE. See #107898