[Foundation] Extract NSURL extensions into a seperate file

Non functional change; purely organization/gardening

Author: phausler

stdlib/public/SDK/Foundation/CMakeLists.txt

@@ -39,6 +39,7 @@ add_swift_library(swiftFoundation ${SWIFT_SDK_OVERLAY_LIBRARY_BUILD_TYPES} IS_SD
   NSStringEncodings.swift
   NSTextCheckingResult.swift
   NSUndoManager.swift
+  NSURL.swift
   NSValue.swift.gyb
   PersonNameComponents.swift
   ReferenceConvertible.swift

stdlib/public/SDK/Foundation/Foundation.swift

@@ -47,17 +47,6 @@ public func NSLog(_ format: String, _ args: CVarArg...) {
   withVaList(args) { NSLogv(format, $0) }
 }
 
-//===----------------------------------------------------------------------===//
-// Mirror/Quick Look Conformance
-//===----------------------------------------------------------------------===//
-
-extension NSURL : CustomPlaygroundQuickLookable {
-  public var customPlaygroundQuickLook: PlaygroundQuickLook {
-    guard let str = absoluteString else { return .text("Unknown URL") }
-    return .url(str)
-  }
-}
-
 //===----------------------------------------------------------------------===//
 // AnyHashable
 //===----------------------------------------------------------------------===//

stdlib/public/SDK/Foundation/NSURL.swift

@@ -0,0 +1,20 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See http://swift.org/LICENSE.txt for license information
+// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+@_exported import Foundation // Clang module
+
+extension NSURL : CustomPlaygroundQuickLookable {
+  public var customPlaygroundQuickLook: PlaygroundQuickLook {
+    guard let str = absoluteString else { return .text("Unknown URL") }
+    return .url(str)
+  }
+}