Change some global constants to type properties to match the Darwin version

- `NSLocale.currentLocaleDidChangeNotification`
- `OperationQueue.defaultMaxConcurrentOperationCount`
- `Notification.Name.NSURLCredentialStorageChanged`

Author: ikesyo

Foundation/NSLocale.swift

@@ -245,8 +245,9 @@ public func <(_ lhs: NSLocale.Key, _ rhs: NSLocale.Key) -> Bool {
 }
 
 
-
-public let NSCurrentLocaleDidChangeNotification: String = "kCFLocaleCurrentLocaleDidChangeNotification"
+public extension NSLocale {
+    public static let currentLocaleDidChangeNotification = NSNotification.Name(rawValue: "kCFLocaleCurrentLocaleDidChangeNotification")
+}
 
 
 extension CFLocale : _NSBridgeable, _SwiftBridgeable {

Foundation/NSOperation.swift

@@ -201,7 +201,9 @@ open class BlockOperation: Operation {
     }
 }
 
-public let NSOperationQueueDefaultMaxConcurrentOperationCount: Int = Int.max
+public extension OperationQueue {
+    public static let defaultMaxConcurrentOperationCount: Int = Int.max
+}
 
 internal struct _OperationList {
     var veryLow = [Operation]()
@@ -332,7 +334,7 @@ open class OperationQueue: NSObject {
                 __concurrencyGate = DispatchSemaphore(value: 1)
             } else {
                 attr = .concurrent
-                if maxConcurrentOperationCount != NSOperationQueueDefaultMaxConcurrentOperationCount {
+                if maxConcurrentOperationCount != OperationQueue.defaultMaxConcurrentOperationCount {
                     __concurrencyGate = DispatchSemaphore(value:maxConcurrentOperationCount)
                 }
             }
@@ -352,7 +354,7 @@ open class OperationQueue: NSObject {
     }
 
 #if DEPLOYMENT_ENABLE_LIBDISPATCH
-    internal init(_queue queue: DispatchQueue, maxConcurrentOperations: Int = NSOperationQueueDefaultMaxConcurrentOperationCount) {
+    internal init(_queue queue: DispatchQueue, maxConcurrentOperations: Int = OperationQueue.defaultMaxConcurrentOperationCount) {
         __underlyingQueue = queue
         maxConcurrentOperationCount = maxConcurrentOperations
         super.init()
@@ -462,7 +464,7 @@ open class OperationQueue: NSObject {
         return count
     }
 
-    open var maxConcurrentOperationCount: Int = NSOperationQueueDefaultMaxConcurrentOperationCount
+    open var maxConcurrentOperationCount: Int = OperationQueue.defaultMaxConcurrentOperationCount
 
     internal var _suspended = false
     open var isSuspended: Bool {

Foundation/NSURLCredentialStorage.swift

@@ -98,12 +98,14 @@ extension URLCredentialStorage {
     public func setDefaultCredential(_ credential: URLCredential, for protectionSpace: URLProtectionSpace, task: URLSessionTask) { NSUnimplemented() }
 }
 
-/*!
-    @const NSURLCredentialStorageChangedNotification
-    @abstract This notification is sent on the main thread whenever
-    the set of stored credentials changes.
-*/
-public let NSURLCredentialStorageChangedNotification: String = "" // NSUnimplemented
+public extension Notification.Name {
+    /*!
+        @const NSURLCredentialStorageChangedNotification
+        @abstract This notification is sent on the main thread whenever
+        the set of stored credentials changes.
+    */
+    public static let NSURLCredentialStorageChanged = NSNotification.Name(rawValue: "") // NSUnimplemented
+}
 
 /*
  *  NSURLCredentialStorageRemoveSynchronizableCredentials - (NSNumber value)

TestFoundation/TestNSLocale.swift

@@ -39,8 +39,8 @@ class TestNSLocale : XCTestCase {
     }
 
     func test_constants() {
-        XCTAssertEqual(NSCurrentLocaleDidChangeNotification, "kCFLocaleCurrentLocaleDidChangeNotification",
-                        "\(NSCurrentLocaleDidChangeNotification) is not equal to kCFLocaleCurrentLocaleDidChangeNotification")
+        XCTAssertEqual(NSLocale.currentLocaleDidChangeNotification.rawValue, "kCFLocaleCurrentLocaleDidChangeNotification",
+                        "\(NSLocale.currentLocaleDidChangeNotification.rawValue) is not equal to kCFLocaleCurrentLocaleDidChangeNotification")
 
         XCTAssertEqual(NSLocale.Key.identifier.rawValue, "kCFLocaleIdentifierKey",
                         "\(NSLocale.Key.identifier.rawValue) is not equal to kCFLocaleIdentifierKey")