Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

mcs/class/corlib/System/Guid.MonoTouch.cs

@@ -0,0 +1,25 @@
+#if MONOTOUCH && FULL_AOT_RUNTIME
+
+using Crimson.CommonCrypto;
+
+namespace System
+{
+	partial struct Guid
+	{
+		public static Guid NewGuid ()
+		{
+			byte[] b = new byte [16];
+			Cryptor.GetRandom (b);
+
+			Guid res = new Guid (b);
+			// Mask in Variant 1-0 in Bit[7..6]
+			res._d = (byte) ((res._d & 0x3fu) | 0x80u);
+			// Mask in Version 4 (random based Guid) in Bits[15..13]
+			res._c = (short) ((res._c & 0x0fffu) | 0x4000u);
+
+			return res;
+		}
+	}
+}
+
+#endif