Make StandardOleMarshalObject ComVisible

src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/StandardOleMarshalObject.Windows.cs

@@ -5,6 +5,7 @@
 
 namespace System.Runtime.InteropServices
 {
+    [ComVisible(true)]
     public class StandardOleMarshalObject : MarshalByRefObject, IMarshal
     {
         private static readonly Guid CLSID_StdMarshal = new Guid("00000017-0000-0000-c000-000000000046");

src/libraries/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.UnitTests/System.Runtime.InteropServices.Tests.csproj

@@ -160,6 +160,7 @@
     <Compile Include="System\Runtime\InteropServices\ProgIdAttributeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\RuntimeEnvironmentTests.cs" />
     <Compile Include="System\Runtime\InteropServices\SafeBufferTests.cs" />
+    <Compile Include="System\Runtime\InteropServices\StandardOleMarshalObjectTests.cs" />
     <Compile Include="System\Runtime\InteropServices\StructLayoutAttributeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\TypeIdentifierAttributeTests.cs" />
     <Compile Include="System\Runtime\InteropServices\UnknownWrapperTests.cs" />

src/libraries/System.Runtime.InteropServices/tests/System.Runtime.InteropServices.UnitTests/System/Runtime/InteropServices/StandardOleMarshalObjectTests.cs

@@ -0,0 +1,39 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Xunit;
+
+namespace System.Runtime.InteropServices.Tests
+{
+    [ConditionalClass(typeof(PlatformDetection), nameof(PlatformDetection.IsBuiltInComEnabled))]
+    public class StandardOleMarshalObjectTests
+    {
+        private static readonly Guid IID_IDispatch = new Guid("00020400-0000-0000-C000-000000000046");
+        [Fact]
+        public void CanGetIDispatchOfDerivedObject()
+        {
+            IntPtr disp = Marshal.GetIDispatchForObject(new DerivedObject());
+            Assert.NotEqual(IntPtr.Zero, disp);
+            Marshal.Release(disp);
+        }
+
+        [Fact]
+        public void CanQueryInterfaceForIDispatchOfDerivedObject()
+        {
+            IntPtr unk = Marshal.GetIUnknownForObject(new DerivedObject());
+            Assert.NotEqual(IntPtr.Zero, unk);
+
+            int hr = Marshal.QueryInterface(unk, IID_IDispatch, out IntPtr disp);
+            Assert.Equal(0, hr);
+            Assert.NotEqual(IntPtr.Zero, disp);
+
+            Marshal.Release(disp);
+            Marshal.Release(unk);
+        }
+
+        [ComVisible(true)]
+        public sealed class DerivedObject : StandardOleMarshalObject
+        {
+        }
+    }
+}