Make RPITITs inherit the assumed_wf_types of their parent method

[compiler-errors]

... and then move the RPITIT well-formedness check to just use the regular logic of wfchecking an associated type.

---

We need to inherit the assumed_wf_types of the RPITIT's parent function in order for the given code to be considered well-formed:

trait Foo {
  fn bar<'a, T>(_: &'a T) -> impl Iterator<Output = &'a T>;
}

Since for &'a T to be WF, we need T: 'a.

In order for this to work for late-bound lifetimes, we need to do some additional mapping of any late-bound lifetimes captured by these assumed wf types. This is because within the body of the function (and thus in the assumed_wf_types), they're represented as ReFree variants of the original late-bound lifetimes declared in the function's generics, but in the RPITIT's GAT, they're represented as "reified" ReEarlyBound vars (duplicated during opaque type lowering). Luckily, the mapping between these two is already stored in the opaque.

Fixes #113796

[bors]

☔ The latest upstream changes (presumably #113801) made this pull request unmergeable. Please resolve the merge conflicts.

[compiler-errors]

r? @spastorino

[spastorino]

This is great Michael, thanks for doing this.

r=me after checking my nits and doing what you prefer with them.

[spastorino]

@bors r+

[bors]

📌 Commit eb85ca976166c66c6ee1e9238b1a8b21b24332f6 has been approved by spastorino

It is now in the queue for this repository.

[bors]

⌛ Testing commit eb85ca976166c66c6ee1e9238b1a8b21b24332f6 with merge 9e7cc5cc95a272c11378af6cded2dcb7b5c2dee3...

[bors]

💔 Test failed - checks-actions

[compiler-errors]

had to bless a test

@bors r=spastorino

[bors]

📌 Commit 744e770 has been approved by spastorino

It is now in the queue for this repository.

[bors]

⌛ Testing commit 744e770 with merge b969b83...

[bors]

☀️ Test successful - checks-actions
Approved by: spastorino
Pushing b969b83 to master...

[rust-timer]

Finished benchmarking commit (b969b83): comparison URL.

Overall result: ❌ regressions - 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)	0.2%	[0.2%, 0.2%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
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)	2.4%	[1.9%, 2.9%]	2
Regressions ❌ (secondary)	1.6%	[1.6%, 1.6%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.6%	[-4.4%, -2.7%]	2
All ❌✅ (primary)	2.4%	[1.9%, 2.9%]	2

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)	2.9%	[2.9%, 2.9%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 652.626s -> 650.727s (-0.29%)