Adopt ‘as’ bridging on Linux.

Foundation/AffineTransform.swift

@@ -476,7 +476,7 @@ open class NSAffineTransform : NSObject, NSCopying, NSSecureCoding {
     }
 }
 
-extension AffineTransform : _ObjectTypeBridgeable {
+extension AffineTransform : _ObjectiveCBridgeable {
     public static func _isBridgedToObjectiveC() -> Bool {
         return true
     }

Foundation/Array.swift

@@ -7,7 +7,7 @@
 // See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 //
 
-extension Array : _ObjectTypeBridgeable {
+extension Array : _ObjectiveCBridgeable {
 
     public typealias _ObjectType = NSArray
     public func _bridgeToObjectiveC() -> _ObjectType {

Foundation/Bridging.swift

@@ -12,29 +12,10 @@
 
 import CoreFoundation
 
-// Support protocols for casting
-public protocol _ObjectBridgeable {
-    func _bridgeToAnyObject() -> AnyObject
-}
-
 public protocol _StructBridgeable {
     func _bridgeToAny() -> Any
 }
 
-/// - Note: This is a similar interface to the _ObjectiveCBridgeable protocol
-public protocol _ObjectTypeBridgeable : _ObjectBridgeable {
-    associatedtype _ObjectType : AnyObject
-
-    func _bridgeToObjectiveC() -> _ObjectType
-
-    static func _forceBridgeFromObjectiveC(_ source: _ObjectType, result: inout Self?)
-
-    @discardableResult
-    static func _conditionallyBridgeFromObjectiveC(_ source: _ObjectType, result: inout Self?) -> Bool
-
-    static func _unconditionallyBridgeFromObjectiveC(_ source: _ObjectType?) -> Self
-}
-
 /// - Note: This does not exist currently on Darwin but it is the inverse correlation to the bridge types such that a 
 /// reference type can be converted via a callout to a conversion method.
 public protocol _StructTypeBridgeable : _StructBridgeable {
@@ -44,7 +25,7 @@ public protocol _StructTypeBridgeable : _StructBridgeable {
 }
 
 // Default adoption of the type specific variants to the Any variant
-extension _ObjectTypeBridgeable {
+extension _ObjectiveCBridgeable {
     public func _bridgeToAnyObject() -> AnyObject {
         return _bridgeToObjectiveC()
     }
@@ -74,8 +55,8 @@ internal protocol _NSBridgeable {
 
 
 /// - Note: This is an internal boxing value for containing abstract structures
-internal final class _SwiftValue : NSObject, NSCopying {
-    internal private(set) var value: Any
+internal final class _SwiftValue : NSObject, NSCopying, _NSSwiftValue {
+    public private(set) var value: Any
 
     static func fetch(_ object: AnyObject?) -> Any? {
         if let obj = object {
@@ -108,10 +89,8 @@ internal final class _SwiftValue : NSObject, NSCopying {
     static func store(_ value: Any) -> NSObject {
         if let val = value as? NSObject {
             return val
-        } else if let val = value as? _ObjectBridgeable {
-            return val._bridgeToAnyObject() as! NSObject
         } else {
-            return _SwiftValue(value)
+            return (value as AnyObject) as! NSObject
         }
     }
 
@@ -144,4 +123,6 @@ internal final class _SwiftValue : NSObject, NSCopying {
     public func copy(with zone: NSZone?) -> Any {
         return _SwiftValue(value)
     }
+
+    public static let null: AnyObject = NSNull()
 }

Foundation/Calendar.swift

@@ -1163,7 +1163,7 @@ extension Calendar : CustomDebugStringConvertible, CustomStringConvertible, Cust
     }
 }
 
-extension Calendar: _ObjectTypeBridgeable {
+extension Calendar: _ObjectiveCBridgeable {
     public typealias _ObjectType = NSCalendar
 
     @_semantics("convertToObjectiveC")

Foundation/CharacterSet.swift

@@ -481,7 +481,7 @@ public struct CharacterSet : ReferenceConvertible, Equatable, Hashable, SetAlgeb
 
 
 // MARK: Objective-C Bridging
-extension CharacterSet : _ObjectTypeBridgeable {
+extension CharacterSet : _ObjectiveCBridgeable {
     public static func _isBridgedToObjectiveC() -> Bool {
         return true
     }

Foundation/Data.swift

@@ -1893,13 +1893,7 @@ extension Data {
 
 /// Provides bridging functionality for struct Data to class NSData and vice-versa.
 
-#if DEPLOYMENT_RUNTIME_SWIFT
-internal typealias DataBridgeType = _ObjectTypeBridgeable
-#else
-internal typealias DataBridgeType = _ObjectiveCBridgeable
-#endif
-
-extension Data : DataBridgeType {
+extension Data : _ObjectiveCBridgeable {
     @_semantics("convertToObjectiveC")
     public func _bridgeToObjectiveC() -> NSData {
         return _backing.bridgedReference(_sliceRange)

Foundation/Date.swift

@@ -230,7 +230,7 @@ extension Date : CustomDebugStringConvertible, CustomStringConvertible, CustomRe
     }
 }
 
-extension Date : _ObjectTypeBridgeable {
+extension Date : _ObjectiveCBridgeable {
     @_semantics("convertToObjectiveC")
     public func _bridgeToObjectiveC() -> NSDate {
         return NSDate(timeIntervalSinceReferenceDate: _time)

Foundation/DateComponents.swift

@@ -352,7 +352,7 @@ extension DateComponents : CustomStringConvertible, CustomDebugStringConvertible
 
 // MARK: - Bridging
 
-extension DateComponents : _ObjectTypeBridgeable {
+extension DateComponents : _ObjectiveCBridgeable {
     public static func _isBridgedToObjectiveC() -> Bool {
         return true
     }

Foundation/DateInterval.swift

@@ -187,7 +187,7 @@ extension DateInterval : CustomStringConvertible, CustomDebugStringConvertible,
     }
 }
 
-extension DateInterval : _ObjectTypeBridgeable {
+extension DateInterval : _ObjectiveCBridgeable {
     public static func _isBridgedToObjectiveC() -> Bool {
         return true
     }

Foundation/Dictionary.swift

@@ -9,7 +9,7 @@
 
 import CoreFoundation
 
-extension Dictionary : _ObjectTypeBridgeable {
+extension Dictionary : _ObjectiveCBridgeable {
 
     public typealias _ObjectType = NSDictionary
     public func _bridgeToObjectiveC() -> _ObjectType {

Foundation/IndexPath.swift

@@ -774,13 +774,7 @@ extension IndexPath : CustomStringConvertible, CustomDebugStringConvertible, Cus
     }
 }
 
-#if DEPLOYMENT_RUNTIME_SWIFT
-internal typealias IndexPathBridgeType = _ObjectTypeBridgeable
-#else
-internal typealias IndexPathBridgeType = _ObjectiveCBridgeable
-#endif
-
-extension IndexPath : IndexPathBridgeType {
+extension IndexPath : _ObjectiveCBridgeable {
     public static func _getObjectiveCType() -> Any.Type {
         return NSIndexPath.self
     }

Foundation/IndexSet.swift

@@ -790,13 +790,7 @@ private func _toNSRange(_ r: Range<IndexSet.Element>) -> NSRange {
     return NSRange(location: r.lowerBound, length: r.upperBound - r.lowerBound)
 }
 
-#if DEPLOYMENT_RUNTIME_SWIFT
-internal typealias IndexSetBridgeType = _ObjectTypeBridgeable
-#else
-internal typealias IndexSetBridgeType = _ObjectiveCBridgeable
-#endif
-
-extension IndexSet : IndexSetBridgeType {
+extension IndexSet : _ObjectiveCBridgeable {
     public static func _getObjectiveCType() -> Any.Type {
         return NSIndexSet.self
     }

Foundation/JSONSerialization.swift

@@ -62,10 +62,12 @@ open class JSONSerialization : NSObject {
                 return true
             }
 
-            if obj is String || obj is NSNull || obj is Int || obj is Bool || obj is UInt ||
-                obj is Int8 || obj is Int16 || obj is Int32 || obj is Int64 ||
-                obj is UInt8 || obj is UInt16 || obj is UInt32 || obj is UInt64 {
-                return true
+            if !(obj is _NSNumberCastingWithoutBridging) {
+              if obj is String || obj is NSNull || obj is Int || obj is Bool || obj is UInt ||
+                  obj is Int8 || obj is Int16 || obj is Int32 || obj is Int64 ||
+                  obj is UInt8 || obj is UInt16 || obj is UInt32 || obj is UInt64 {
+                  return true
+              }
             }
 
             // object is a Double and is not NaN or infinity
@@ -315,12 +317,19 @@ private struct JSONWriter {
         self.writer = writer
     }
 
-    mutating func serializeJSON(_ obj: Any?) throws {
+    mutating func serializeJSON(_ object: Any?) throws {
+
+        var toSerialize = object
 
-        guard let obj = obj else {
+        if let number = toSerialize as? _NSNumberCastingWithoutBridging {
+            toSerialize = number._swiftValueOfOptimalType
+        }
+
+        guard let obj = toSerialize else {
             try serializeNull()
             return
         }
+
         // For better performance, the most expensive conditions to evaluate should be last.
         switch (obj) {
         case let str as String:

Foundation/Locale.swift

@@ -439,7 +439,7 @@ public struct Locale : CustomStringConvertible, CustomDebugStringConvertible, Ha
 }
 
 
-extension Locale : _ObjectTypeBridgeable {
+extension Locale : _ObjectiveCBridgeable {
     public static func _isBridgedToObjectiveC() -> Bool {
         return true
     }

Foundation/Measurement.swift

@@ -206,14 +206,8 @@ extension Measurement {
 
 // Implementation note: similar to NSArray, NSDictionary, etc., NSMeasurement's import as an ObjC generic type is suppressed by the importer. Eventually we will need a more general purpose mechanism to correctly import generic types.
 
-#if DEPLOYMENT_RUNTIME_SWIFT
-internal typealias MeasurementBridgeType = _ObjectTypeBridgeable
-#else
-internal typealias MeasurementBridgeType = _ObjectiveCBridgeable
-#endif
-
 @available(macOS 10.12, iOS 10.0, watchOS 3.0, tvOS 10.0, *)
-extension Measurement : MeasurementBridgeType {
+extension Measurement : _ObjectiveCBridgeable {
     @_semantics("convertToObjectiveC")
     public func _bridgeToObjectiveC() -> NSMeasurement {
         return NSMeasurement(doubleValue: value, unit: unit)

Foundation/NSArray.swift

@@ -334,13 +334,12 @@ open class NSArray : NSObject, NSCopying, NSMutableCopying, NSSecureCoding, NSCo
                 if val1 != val2 {
                     return false
                 }
-            } else if let val1 = object(at: idx) as? _ObjectBridgeable,
-                let val2 = otherArray[idx] as? _ObjectBridgeable {
-                if !(val1._bridgeToAnyObject() as! NSObject).isEqual(val2._bridgeToAnyObject()) {
+            } else {
+              let val1 = object(at: idx)
+              let val2 = otherArray[idx]
+                if !((val1 as AnyObject) as! NSObject).isEqual(val2 as AnyObject) {
                     return false
                 }
-            } else {
-                return false
             }
         }
 

Foundation/NSDecimalNumber.swift

@@ -297,28 +297,28 @@ open class NSDecimalNumber : NSNumber {
     // return 'd' for double
 
     open override var int8Value: Int8 {
-        return Int8(decimal.doubleValue)
+        return Int8(exactly: decimal.doubleValue) ?? 0 as Int8
     }
     open override var uint8Value: UInt8 {
-        return UInt8(decimal.doubleValue)
+        return UInt8(exactly: decimal.doubleValue) ?? 0 as UInt8
     }
     open override var int16Value: Int16 {
-        return Int16(decimal.doubleValue)
+        return Int16(exactly: decimal.doubleValue) ?? 0 as Int16
     }
     open override var uint16Value: UInt16 {
-        return UInt16(decimal.doubleValue)
+        return UInt16(exactly: decimal.doubleValue) ?? 0 as UInt16
     }
     open override var int32Value: Int32 {
-        return Int32(decimal.doubleValue)
+        return Int32(exactly: decimal.doubleValue) ?? 0 as Int32
     }
     open override var uint32Value: UInt32 {
-        return UInt32(decimal.doubleValue)
+        return UInt32(exactly: decimal.doubleValue) ?? 0 as UInt32
     }
     open override var int64Value: Int64 {
-        return Int64(decimal.doubleValue)
+        return Int64(exactly: decimal.doubleValue) ?? 0 as Int64
     }
     open override var uint64Value: UInt64 {
-        return UInt64(decimal.doubleValue)
+        return UInt64(exactly: decimal.doubleValue) ?? 0 as UInt64
     }
     open override var floatValue: Float {
         return Float(decimal.doubleValue)
@@ -330,17 +330,20 @@ open class NSDecimalNumber : NSNumber {
         return !decimal.isZero
     }
     open override var intValue: Int {
-        return Int(decimal.doubleValue)
+        return Int(exactly: decimal.doubleValue) ?? 0 as Int
     }
     open override var uintValue: UInt {
-        return UInt(decimal.doubleValue)
+        return UInt(exactly: decimal.doubleValue) ?? 0 as UInt
     }
 
     open override func isEqual(_ value: Any?) -> Bool {
         guard let other = value as? NSDecimalNumber else { return false }
         return self.decimal == other.decimal
     }
 
+    override var _swiftValueOfOptimalType: Any {
+      return decimal
+    }
 }
 
 // return an approximate double value

Foundation/NSDictionary.swift

@@ -395,13 +395,12 @@ open class NSDictionary : NSObject, NSCopying, NSMutableCopying, NSSecureCoding,
                 if otherValue != value {
                     return false
                 }
-            } else if let otherBridgeable = otherDictionary[key as! AnyHashable] as? _ObjectBridgeable,
-                      let bridgeable = object(forKey: key)! as? _ObjectBridgeable {
-                if !(otherBridgeable._bridgeToAnyObject() as! NSObject).isEqual(bridgeable._bridgeToAnyObject()) {
+            } else {
+              let otherBridgeable = otherDictionary[key as! AnyHashable]
+              let bridgeable = object(forKey: key)!
+                if !((otherBridgeable as AnyObject) as! NSObject).isEqual(bridgeable as AnyObject) {
                     return false
                 }
-            } else {
-                return false
             }
         }