KeyPath causes a compiler crash on an existential root

[StevenSorial]

Describe the bug
KeyPath causes a compiler crash on an array of existentials while a normal closure doesn't

Steps To Reproduce
Steps to reproduce the behavior:

import Foundation

protocol Brand {
  var name: String { get }
}

protocol Car {
  associatedtype BrandType: Brand
  var brand: BrandType { get }
}

func test() {
  let cars: [any Car] = []
  
  let brandsByClosure: [any Brand] = cars.map { $0.brand } // Works
  let brandsByKey: [any Brand] = cars.map(\.brand) // Compiler failure

  let sortedByClosure: [any Car] = cars.sorted { $0.brand.name < $1.brand.name } // Works
  let sortedByKey: [any Car] = cars.sorted(using: KeyPathComparator(\.brand.name)) // Compiler failure
}

Expected behavior
Both forms of map and sorted should work

Environment (please fill out the following information)

• OS: macOS 12.5
• Xcode Version/Tag/Branch: Xcode 14.0 beta 3

[StevenSorial]

Still crashes in Xcode 14.0 beta 4
Feedback filed: FB10900087

[theblixguy]

Smaller reproducer:

protocol P {
  associatedtype Assoc
  var value: Assoc { get }
}

func test() {
  let ps: [any P] = []
  _ = ps.map(\.value) // crash
}

[AnthonyLatsis]

Possibly a duplicate of #58289.