Add trimming test for Marshal.StructureToPtr with ByVal DateTime arra…

src/libraries/System.Runtime.InteropServices/tests/TrimmingTests/MarshalStructureToPtrByValDateArray.cs

@@ -0,0 +1,43 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+// Regression test for https://github.com/dotnet/runtime/issues/127952
+// Marshal.StructureToPtr / Marshal.DestroyStructure on a struct containing a
+// ByValArray of DateTime values requires the DateMarshaler stub-helper to
+// survive trimming.  Without the fix this throws:
+//   System.Security.VerificationException: Method
+//   System.StubHelpers.StubHelpers.FreeArrayContents: type argument
+//   'System.StubHelpers.DateMarshaler' violates the constraint of type
+//   parameter 'TMarshaler'.
+
+using System;
+using System.Runtime.InteropServices;
+
+var structure = new StructWithDateArray()
+{
+    array = new DateTime[]
+    {
+        DateTime.Now, DateTime.Now
+    }
+};
+
+int size = Marshal.SizeOf(structure);
+IntPtr memory = Marshal.AllocHGlobal(size);
+try
+{
+    Marshal.StructureToPtr(structure, memory, false);
+    Marshal.StructureToPtr(structure, memory, true);
+}
+finally
+{
+    Marshal.DestroyStructure(memory, structure.GetType());
+    Marshal.FreeHGlobal(memory);
+}
+
+return 100;
+
+public struct StructWithDateArray
+{
+    [MarshalAs(UnmanagedType.ByValArray, SizeConst = 2)]
+    public DateTime[] array;
+}

src/libraries/System.Runtime.InteropServices/tests/TrimmingTests/System.Runtime.InteropServices.TrimmingTests.proj

@@ -26,6 +26,11 @@
     <TestConsoleAppSourceFiles Include="TypeMap.cs" NativeAotOnly="true">
       <EnabledProperties>IlcGenerateMstatFile;IlcGenerateDgmlFile</EnabledProperties>
     </TestConsoleAppSourceFiles>
+
+    <!-- Regression test for https://github.com/dotnet/runtime/issues/127952 -->
+    <!-- Marshal.StructureToPtr on a struct containing a ByValArray of DateTime values -->
+    <!-- is expected to fail on tvos-arm64 until the underlying issue is fixed. -->
+    <TestConsoleAppSourceFiles Include="MarshalStructureToPtrByValDateArray.cs" />
   </ItemGroup>
 
   <Import Project="$([MSBuild]::GetPathOfFileAbove(Directory.Build.targets))" />