Add hostservices translation support for clr 4 task host

src/Framework/ITranslator.cs

@@ -84,6 +84,12 @@ internal interface ITranslator : IDisposable
         /// from NodePacketTypeExtensions.PacketVersion when nodes are running different MSBuild versions.
         /// The negotiated version is used to conditionally serialize/deserialize fields that may
         /// not be supported by older packet versions.
+        /// Special values:
+        /// <b>0</b>: Indicates Framework-to-Framework (e.g. TaskHost with CLR4 runtime) task host communication.
+        /// A value of 0 means version match is guaranteed since both processes are shipped together (version match validation on handshake).
+        /// <b>1</b>: Base version for .NET task host communication without newer features. Skips serialization of AppDomain.
+        /// <b>2+</b>: .NET task host communication with support for additional fields like HostServices,
+        /// TargetName, and ProjectFile in TaskHostConfiguration.
         /// </remarks>
         byte NegotiatedPacketVersion { get; set; }
 

src/Shared/TaskHostConfiguration.cs

@@ -507,11 +507,14 @@ public void Translate(ITranslator translator)
             translator.Translate(ref _projectFileOfTask);
             translator.Translate(ref _taskName);
             translator.Translate(ref _taskLocation);
-            if (translator.NegotiatedPacketVersion >= 2)
+
+            // Version 0 = Framework-to-Framework (e.g. CLR4),
+            // Version 2+ = .NET task host with support of translation for these fields.
+            if (translator.NegotiatedPacketVersion == 0 || translator.NegotiatedPacketVersion >= 2)
             {
                 translator.Translate(ref _targetName);
                 translator.Translate(ref _projectFile);
-#if !NET35    
+#if !NET35
                 translator.Translate(ref _hostServices);
 #endif
             }