New value types for Calendar, TimeZone, and Locale

As part of the extensive work on value types in Foundation this year, we
decided to also add value types for these three key classes. In addition
to adding value semantics, the API was extensively audited to improve
Swift interop (especially Calendar).

rdar://26628184

Author: parkera

apinotes/Foundation.apinotes

@@ -647,7 +647,15 @@ Classes:
   - Selector: 'stringFromByteCount:'
     SwiftName: stringFromByteCount(_:)
     MethodKind: Instance
+- Name: NSLocale
+  SwiftName: NSLocale
+  SwiftBridge: Locale
+- Name: NSTimeZone
+  SwiftName: NSTimeZone
+  SwiftBridge: TimeZone
 - Name: NSCalendar
+  SwiftName: NSCalendar
+  SwiftBridge: Calendar
   Methods:
   - Selector: 'dateWithEra:year:month:day:hour:minute:second:nanosecond:'
     SwiftName: date(era:year:month:day:hour:minute:second:nanosecond:)
@@ -1114,9 +1122,9 @@ Tags:
 - Name: NSByteCountFormatterCountStyle
   SwiftName: ByteCountFormatter.CountStyle
 - Name: NSCalendarUnit
-  SwiftName: Calendar.Unit
+  SwiftName: NSCalendar.Unit
 - Name: NSCalendarOptions
-  SwiftName: Calendar.Options
+  SwiftName: NSCalendar.Options
 - Name: NSDecodingFailurePolicy
   SwiftName: NSCoder.DecodingFailurePolicy
 - Name: NSComparisonPredicateOptions
@@ -1229,7 +1237,7 @@ Tags:
   Availability: nonswift
   AvailabilityMsg: Use 'NSTextCheckingResult.CheckingType'
 - Name: NSTimeZoneNameStyle
-  SwiftName: TimeZone.NameStyle
+  SwiftName: NSTimeZone.NameStyle
 - Name: NSURLCacheStoragePolicy
   SwiftName: URLCache.StoragePolicy
 - Name: NSURLCredentialPersistence
@@ -1281,7 +1289,7 @@ Tags:
 - Name: NSDateComponentsFormatterZeroFormattingBehavior
   SwiftName: DateComponentsFormatter.ZeroFormattingBehavior
 - Name: NSLocaleLanguageDirection
-  SwiftName: Locale.LanguageDirection
+  SwiftName: NSLocale.LanguageDirection
 - Name: NSNetServiceOptions
   SwiftName: NSNetService.Options
 - Name: NSPointerFunctionsOptions
@@ -1348,13 +1356,13 @@ Typedefs:
 - Name: NSBackgroundActivityCompletionHandler
   SwiftName: NSBackgroundActivityScheduler.CompletionHandler
 - Name: NSCalendarIdentifier
-  SwiftName: Calendar.Identifier
+  SwiftName: NSCalendar.Identifier
 - Name: NSItemProviderCompletionHandler
   SwiftName: NSItemProvider.CompletionHandler
 - Name: NSItemProviderLoadHandler
   SwiftName: NSItemProvider.LoadHandler
 - Name: NSLocaleKey
-  SwiftName: Locale.Key
+  SwiftName: NSLocale.Key
 - Name: NSNotificationName
   SwiftName: NSNotification.Name
 - Name: NSProgressFileOperationKind
@@ -1423,7 +1431,7 @@ Globals:
 - Name: NSItemProviderErrorDomain
   SwiftName: NSItemProvider.errorDomain
 - Name: NSCurrentLocaleDidChangeNotification
-  SwiftName: Locale.currentLocaleDidChangeNotification
+  SwiftName: NSLocale.currentLocaleDidChangeNotification
 - Name: NSNetServicesErrorDomain
   SwiftName: NSNetService.errorDomain
 - Name: NSNetServicesErrorCode

stdlib/private/StdlibUnittestFoundationExtras/StdlibUnittestFoundationExtras.swift

@@ -13,25 +13,25 @@
 import ObjectiveC
 import Foundation
 
-internal var _temporaryLocaleCurrentLocale: Locale? = nil
+internal var _temporaryLocaleCurrentLocale: NSLocale? = nil
 
-extension Locale {
+extension NSLocale {
   @objc
-  public class func _swiftUnittest_currentLocale() -> Locale {
+  public class func _swiftUnittest_currentLocale() -> NSLocale {
     return _temporaryLocaleCurrentLocale!
   }
 }
 
 public func withOverriddenLocaleCurrentLocale<Result>(
-  _ temporaryLocale: Locale,
+  _ temporaryLocale: NSLocale,
   _ body: @noescape () -> Result
 ) -> Result {
   let oldMethod = class_getClassMethod(
-    Locale.self, #selector(getter: Locale.current))
+    NSLocale.self, #selector(getter: NSLocale.current))
   precondition(oldMethod != nil, "could not find +[Locale currentLocale]")
 
   let newMethod = class_getClassMethod(
-    Locale.self, #selector(Locale._swiftUnittest_currentLocale))
+    NSLocale.self, #selector(NSLocale._swiftUnittest_currentLocale))
   precondition(newMethod != nil, "could not find +[Locale _swiftUnittest_currentLocale]")
 
   precondition(_temporaryLocaleCurrentLocale == nil,
@@ -51,11 +51,11 @@ public func withOverriddenLocaleCurrentLocale<Result>(
   _ body: @noescape () -> Result
 ) -> Result {
   precondition(
-    Locale.availableLocaleIdentifiers.contains(temporaryLocaleIdentifier),
+    NSLocale.availableLocaleIdentifiers.contains(temporaryLocaleIdentifier),
     "requested locale \(temporaryLocaleIdentifier) is not available")
 
   return withOverriddenLocaleCurrentLocale(
-    Locale(localeIdentifier: temporaryLocaleIdentifier), body)
+    NSLocale(localeIdentifier: temporaryLocaleIdentifier), body)
 }
 
 /// Executes the `body` in an autorelease pool if the platform does not

stdlib/public/SDK/Foundation/CMakeLists.txt

@@ -7,6 +7,9 @@ add_swift_library(swiftFoundation ${SWIFT_SDK_OVERLAY_LIBRARY_BUILD_TYPES} IS_SD
   ExtraStringAPIs.swift
   ReferenceConvertible.swift
   AffineTransform.swift
+  Calendar.swift
+  TimeZone.swift
+  Locale.swift
   CharacterSet.swift
   Date.swift
   DateComponents.swift