Resolve ILLink warnings in System.ComponentModel.TypeConverter (Final)

src/libraries/System.ComponentModel.TypeConverter/ref/System.ComponentModel.TypeConverter.cs

@@ -864,6 +864,7 @@ protected virtual void Dispose(bool disposing) { }
         public virtual object GetService(System.Type service) { throw null; }
         public override string ToString() { throw null; }
     }
+    [System.Diagnostics.CodeAnalysis.DynamicallyAccessedMembersAttribute(System.Diagnostics.CodeAnalysis.DynamicallyAccessedMemberTypes.PublicConstructors)]
     public partial class MaskedTextProvider : System.ICloneable
     {
         public MaskedTextProvider(string mask) { }

src/libraries/System.ComponentModel.TypeConverter/src/System/ComponentModel/MaskedTextProvider.cs

@@ -1,10 +1,10 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System;
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Runtime.Versioning;
 using System.Text;
@@ -19,6 +19,7 @@ namespace System.ComponentModel
     /// to the test string itself, since mask literals cannot be modified (i.e: replacing on a literal position
     /// will actually replace on the nearest edit position forward).
     /// </summary>
+    [DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicConstructors)] // needed by Clone() to preserve derived ctors
     public class MaskedTextProvider : ICloneable
     {
         ///