Filter out compiler generated types for Add-Type -PassThru (#18095)

src/Microsoft.PowerShell.Commands.Utility/commands/utility/AddType.cs

@@ -13,6 +13,7 @@ using System.Management.Automation;
 using System.Management.Automation.Internal;
 using System.Management.Automation.Security;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 using System.Runtime.Loader;
 using System.Security;
 using System.Text;
@@ -891,7 +892,14 @@ namespace Microsoft.PowerShell.Commands
 
         private void WriteTypes(Assembly assembly)
         {
-            WriteObject(assembly.GetTypes(), true);
+            foreach (Type type in assembly.GetTypes())
+            {
+                // We only write out types that are not auto-generated by compiler.
+                if (type.GetCustomAttribute<CompilerGeneratedAttribute>() is null)
+                {
+                    WriteObject(type);
+                }
+            }
         }
 
         #endregion LoadAssembly