[stdlib] Apply minor review notes

Author: lorentey

stdlib/public/core/MemoryLayout.swift

@@ -239,9 +239,6 @@ extension MemoryLayout {
   @_transparent
   @_unavailableInEmbedded
   public static func offset(of key: PartialKeyPath<T>) -> Int? {
-    // FIXME(noncopyableGenerics): The new (implicit) `where T: Copyable`
-    // extension constraint currently changes the mangling of this from a
-    // standalone function to an extension method.
     return key._storedInlineOffset
   }
 }

stdlib/public/core/MigrationSupport.swift

@@ -2,7 +2,7 @@
 //
 // This source file is part of the Swift.org open source project
 //
-// Copyright (c) 2014 - 2024 Apple Inc. and the Swift project authors
+// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
 // Licensed under Apache License v2.0 with Runtime Library Exception
 //
 // See https://swift.org/LICENSE.txt for license information

stdlib/public/core/Optional.swift

@@ -132,12 +132,12 @@ public enum Optional<Wrapped: ~Copyable>: ~Copyable {
   case some(Wrapped)
 }
 
+extension Optional: Copyable /* where Wrapped: Copyable */ {}
+
 extension Optional: Sendable where Wrapped: ~Copyable & Sendable { }
 
 extension Optional: _BitwiseCopyable where Wrapped: _BitwiseCopyable { }
 
-extension Optional: Copyable /* where Wrapped: Copyable */ {}
-
 @_preInverseGenerics
 extension Optional: ExpressibleByNilLiteral where Wrapped: ~Copyable {
   /// Creates an instance initialized with `nil`.