[stdlib] Modernize Set and Dictionary internals

stdlib/public/core/Hashing.swift

@@ -39,25 +39,19 @@ internal func _stdlib_NSObject_isEqual(_ lhs: AnyObject, _ rhs: AnyObject) -> Bo
 ///
 /// Accesses the underlying raw memory as Unmanaged<AnyObject> using untyped
 /// memory accesses. The memory remains bound to managed AnyObjects.
-@_fixed_layout // FIXME(sil-serialize-all)
-@usableFromInline // FIXME(sil-serialize-all)
 internal struct _UnmanagedAnyObjectArray {
   /// Underlying pointer.
-  @usableFromInline // FIXME(sil-serialize-all)
   internal var value: UnsafeMutableRawPointer
 
-  @inlinable // FIXME(sil-serialize-all)
   internal init(_ up: UnsafeMutablePointer<AnyObject>) {
     self.value = UnsafeMutableRawPointer(up)
   }
 
-  @inlinable // FIXME(sil-serialize-all)
   internal init?(_ up: UnsafeMutablePointer<AnyObject>?) {
     guard let unwrapped = up else { return nil }
     self.init(unwrapped)
   }
 
-  @inlinable // FIXME(sil-serialize-all)
   internal subscript(i: Int) -> AnyObject {
     get {
       let unmanaged = value.load(

stdlib/public/core/SequenceAlgorithms.swift

@@ -43,7 +43,7 @@ extension Sequence {
   /// list consisting of indices of names with five or fewer letters.
   ///
   ///     let names: Set = ["Sofia", "Camilla", "Martina", "Mateo", "Nicolás"]
-  ///     var shorterIndices: [SetIndex<String>] = []
+  ///     var shorterIndices: [Set<String>.Index] = []
   ///     for (i, name) in zip(names.indices, names) {
   ///         if name.count <= 5 {
   ///             shorterIndices.append(i)