Swift 5.7: incorrect compiler error with opaque result types and primary associated types

[groue]

Describe the bug

The compiler produces an error when it should not, in a context that involves opaque result types and primary associated types

To Reproduce

Steps to reproduce the behavior:

1. Compile this Swift snippet with Xcode 14 beta:

   protocol Cursor<Element> {
       associatedtype Element
   }
   
   extension Cursor {
       func flatMap1<SegmentOfResult>(_ transform: @escaping (Element) throws -> SegmentOfResult)
       -> some Cursor<SegmentOfResult.Element>
       where SegmentOfResult: Cursor
       {
           // ❌ Return type of instance method 'flatMap1' requires that
           // 'SegmentOfResult.Element' conform to '(some Cursor).Element'
           map(transform).joined()
       }
   
       func flatMap2<T>(_ transform: @escaping (Element) throws -> some Cursor<T>)
       -> some Cursor<T>
       {
           // ❌ Return type of instance method 'flatMap2' requires that 'T' conform
           // to '(some Cursor).Element'
           map(transform).joined()
       }
   
       func map<T>(_ transform: @escaping (Element) throws -> T) -> some Cursor<T> {
           fatalError("not implemented")
       }
   }
   
   extension Cursor where Element: Cursor {
       func joined() -> some Cursor<Element.Element> {
           fatalError("not implemented")
       }
   }

2. See the erroneous compiler errors on the flatMap1 and flatMap2 methods.

Expected behavior

1. flatMap1 should compile
2. flatMap2 should probably compile as well (but I'm less comfortable with closure arguments that return some, so I'm less sure).

Environment (please complete the following information):

• OS: macOS 12.4
• Xcode Version 14.0 beta (14A5228q)