Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

external/rx/Rx/NET/Source/System.Reactive.Interfaces/AssemblyFileVersionAttribute.cs

@@ -0,0 +1,22 @@
+// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
+
+#if NO_ASSEMBLYFILEVERSIONATTRIBUTE
+namespace System.Reflection
+{
+    [AttributeUsage(AttributeTargets.Assembly)]
+    public class AssemblyFileVersionAttribute : Attribute
+    {
+        private readonly string _version;
+
+        public AssemblyFileVersionAttribute(string version)
+        {
+             _version = version;     
+        }
+
+        public string Version
+        {
+            get { return _version; }
+        }
+    }
+}
+#endif