extendingOrTruncating -> truncatingIfNeeded to satisfy latest Swift4 changes

Sources/CryptoSwift/AES.swift

@@ -422,7 +422,7 @@ fileprivate extension AES {
         var p: UInt8 = 1, q: UInt8 = 1
 
         repeat {
-            p = p ^ (UInt8(extendingOrTruncating: Int(p) << 1) ^ ((p & 0x80) == 0x80 ? 0x1B : 0))
+            p = p ^ (UInt8(truncatingIfNeeded: Int(p) << 1) ^ ((p & 0x80) == 0x80 ? 0x1B : 0))
             q ^= q << 1
             q ^= q << 2
             q ^= q << 4

Sources/CryptoSwift/Collection+Extension.swift

@@ -68,7 +68,7 @@ extension Collection where Self.Iterator.Element == UInt8, Self.Index == Int {
         }
 
         if size == 1 {
-            return T(extendingOrTruncating: UInt64(bytes[0]))
+            return T(truncatingIfNeeded: UInt64(bytes[0]))
         }
 
         var result: T = 0

Sources/CryptoSwift/Rabbit.swift

@@ -160,26 +160,26 @@ public final class Rabbit: BlockCipher {
     private func g(_ j: Int) -> UInt32 {
         let sum = x[j] &+ c[j]
         let square = UInt64(sum) * UInt64(sum)
-        return UInt32.init(extendingOrTruncating: square ^ (square >> 32))
+        return UInt32.init(truncatingIfNeeded: square ^ (square >> 32))
     }
 
     fileprivate func nextOutput() -> Array<UInt8> {
         nextState()
 
         var output16 = [UInt16](repeating: 0, count: Rabbit.blockSize / 2)
-        output16[7] = UInt16(extendingOrTruncating: x[0]) ^ UInt16(extendingOrTruncating: x[5] >> 16)
-        output16[6] = UInt16(extendingOrTruncating: x[0] >> 16) ^ UInt16(extendingOrTruncating: x[3])
-        output16[5] = UInt16(extendingOrTruncating: x[2]) ^ UInt16(extendingOrTruncating: x[7] >> 16)
-        output16[4] = UInt16(extendingOrTruncating: x[2] >> 16) ^ UInt16(extendingOrTruncating: x[5])
-        output16[3] = UInt16(extendingOrTruncating: x[4]) ^ UInt16(extendingOrTruncating: x[1] >> 16)
-        output16[2] = UInt16(extendingOrTruncating: x[4] >> 16) ^ UInt16(extendingOrTruncating: x[7])
-        output16[1] = UInt16(extendingOrTruncating: x[6]) ^ UInt16(extendingOrTruncating: x[3] >> 16)
-        output16[0] = UInt16(extendingOrTruncating: x[6] >> 16) ^ UInt16(extendingOrTruncating: x[1])
+        output16[7] = UInt16(truncatingIfNeeded: x[0]) ^ UInt16(truncatingIfNeeded: x[5] >> 16)
+        output16[6] = UInt16(truncatingIfNeeded: x[0] >> 16) ^ UInt16(truncatingIfNeeded: x[3])
+        output16[5] = UInt16(truncatingIfNeeded: x[2]) ^ UInt16(truncatingIfNeeded: x[7] >> 16)
+        output16[4] = UInt16(truncatingIfNeeded: x[2] >> 16) ^ UInt16(truncatingIfNeeded: x[5])
+        output16[3] = UInt16(truncatingIfNeeded: x[4]) ^ UInt16(truncatingIfNeeded: x[1] >> 16)
+        output16[2] = UInt16(truncatingIfNeeded: x[4] >> 16) ^ UInt16(truncatingIfNeeded: x[7])
+        output16[1] = UInt16(truncatingIfNeeded: x[6]) ^ UInt16(truncatingIfNeeded: x[3] >> 16)
+        output16[0] = UInt16(truncatingIfNeeded: x[6] >> 16) ^ UInt16(truncatingIfNeeded: x[1])
 
         var output8 = Array<UInt8>(repeating: 0, count: Rabbit.blockSize)
         for j in 0 ..< output16.count {
-            output8[j * 2] = UInt8(extendingOrTruncating: output16[j] >> 8)
-            output8[j * 2 + 1] = UInt8(extendingOrTruncating: output16[j])
+            output8[j * 2] = UInt8(truncatingIfNeeded: output16[j] >> 8)
+            output8[j * 2 + 1] = UInt8(truncatingIfNeeded: output16[j])
         }
         return output8
     }