Imported Upstream version 6.0.0.172

Former-commit-id: f3cc9b82f3e5bd8f0fd3ebc098f789556b44e9cd

mcs/class/corlib/corefx/DateTime.cs

@@ -0,0 +1,28 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Runtime;
+using System.Runtime.InteropServices;
+using System.Runtime.CompilerServices;
+
+namespace System
+{
+    partial struct DateTime
+    {
+        public static DateTime UtcNow 
+        {
+            get 
+            {
+                long ticks = GetSystemTimeAsFileTime();
+                return new DateTime(((UInt64)(ticks + FileTimeOffset)) | KindUtc);
+            }
+        }
+
+        [MethodImplAttribute(MethodImplOptions.InternalCall)]
+        internal static extern long GetSystemTimeAsFileTime();
+
+        internal Int64 ToBinaryRaw() => (Int64)_dateData;
+    }
+}