[dotnet-svcutil] add ObservableCollection assembly to default referenced assemblies

src/dotnet-svcutil/lib/src/Bootstrapper/SvcutilBootstrapper.cs

@@ -149,7 +149,8 @@ internal async Task GenerateProjectAsync(bool keepBootstrapperDir, ILogger logge
 
             // Don't treat warnings as errors so the bootstrapper will succeed as often as possible.
             this.MSBuildProj.ClearWarningsAsErrors();
-
+            // Suppress harmless MSB3277 assembly version conflicts resolved automatically by MSBuild.
+            this.MSBuildProj.SuppressWarningMSB3277();
             await this.MSBuildProj.SaveAsync(logger, cancellationToken).ConfigureAwait(false);
         }
 

src/dotnet-svcutil/lib/src/CommandProcessorOptions.cs

@@ -896,7 +896,11 @@ private void AddStdLibraries(Dictionary<string, Type> foundCollectionTypes, Dict
             {
                 typeof(int), // System.Runtime.dll
                 typeof(System.ServiceModel.ChannelFactory), // System.ServiceModel (svcutil private code)
-                typeof(System.Net.HttpStatusCode) // netstandard.dll, System.Net.Primitives.dll
+                typeof(System.Net.HttpStatusCode), // netstandard.dll, System.Net.Primitives.dll
+                typeof(System.Collections.Generic.LinkedList<>), // System.Collections.dll
+                typeof(System.Collections.ObjectModel.ObservableCollection<>), // System.ObjectModel.dll
+                typeof(System.Collections.SortedList), // System.Collections.NonGeneric.dll
+                typeof(System.Collections.Specialized.ListDictionary) // System.Collections.Specialized.dll
             };
 
             foreach (var type in coreTypes)

src/dotnet-svcutil/lib/src/Shared/MSBuildProj.cs

@@ -636,6 +636,11 @@ public void ClearWarningsAsErrors()
             SetPropertyValue("WarningsAsErrors", string.Empty);
         }
 
+        public void SuppressWarningMSB3277()
+        {
+            SetPropertyValue("NoWarn", "$(NoWarn);MSB3277");
+        }
+
         private void UpdateTargetFramework(string targetFramework)
         {
             if (_targetFramework != targetFramework && !string.IsNullOrWhiteSpace(targetFramework))