Conform Never to Identifiable

Incorporating into `release/5.5` as part of evolution review discussion. This can be reverted if the Core team decides to not accept this change.

rdar://75988520

Author: Kyle Macomber

stdlib/public/core/Policy.swift

@@ -34,6 +34,11 @@ extension Never: Error {}
 
 extension Never: Equatable, Comparable, Hashable {}
 
+@available(macOS 12.0, iOS 15.0, watchOS 8.0, tvOS 15.0, *)
+extension Never: Identifiable {
+  public var id: Never { fatalError() }
+}
+
 //===----------------------------------------------------------------------===//
 // Standardized aliases
 //===----------------------------------------------------------------------===//

test/api-digester/stability-stdlib-abi-without-asserts.test

@@ -57,3 +57,4 @@ Protocol CodingKey has added inherited protocol Sendable
 Protocol CodingKey has generic signature change from <Self : Swift.CustomDebugStringConvertible, Self : Swift.CustomStringConvertible> to <Self : Swift.CustomDebugStringConvertible, Self : Swift.CustomStringConvertible, Self : Swift.Sendable>
 Protocol Error has added inherited protocol Sendable
 Protocol Error has generic signature change from to <Self : Swift.Sendable>
+Enum Never has added a conformance to an existing protocol Identifiable