[release/6.0] [mono][interp] Add unbox when calling valuetype method through delegate (#79819)

* [mono][interp] Add unbox when calling valuetype method through delegate

If we are calling an open instance delegate, where the target method is on a valuetype, we will need to unbox this pointer.

* [tests] Add regression test

* [tests] Disable test on fullaot

Author: BrzVlad

src/mono/mono/mini/interp/interp.c

@@ -3450,7 +3450,12 @@ interp_exec_method (InterpFrame *frame, ThreadContext *context, FrameClauseArgs
 					} else if (del_imethod->method->flags & METHOD_ATTRIBUTE_VIRTUAL && !del->target && !m_class_is_valuetype (del_imethod->method->klass)) {
 						// 'this' is passed dynamically, we need to recompute the target method
 						// with each call
-						del_imethod = get_virtual_method (del_imethod, LOCAL_VAR (call_args_offset + MINT_STACK_SLOT_SIZE, MonoObject*)->vtable);
+						MonoObject *obj = LOCAL_VAR (call_args_offset + MINT_STACK_SLOT_SIZE, MonoObject*);
+						del_imethod = get_virtual_method (del_imethod, obj->vtable);
+						if (m_class_is_valuetype (obj->vtable->klass) && m_class_is_valuetype (del_imethod->method->klass)) {
+							// We are calling into a value type method, `this` needs to be unboxed
+							LOCAL_VAR (call_args_offset + MINT_STACK_SLOT_SIZE, gpointer) = mono_object_unbox_internal (obj);
+						}
 					} else {
 						del->interp_invoke_impl = del_imethod;
 					}

src/tests/JIT/Regression/JitBlue/Runtime_79354/Runtime_79354.cs

@@ -0,0 +1,45 @@
+// 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.Reflection;
+
+public interface IGetContents {
+    (string, int, string) GetContents();
+}
+
+public struct MyStruct : IGetContents {
+    public string s1;
+    public int a;
+    public string s2;
+
+    public (string, int, string) GetContents()
+    {
+        return (s1, a, s2);
+    }
+}
+
+public class Program {
+
+    public delegate (string, int, string) MyDelegate(IGetContents arg);
+
+    public static int Main(string[] args)
+    {
+        MyStruct str = new MyStruct();
+        str.s1 = "test1";
+        str.a = 42;
+        str.s2 = "test2";
+
+        MethodInfo mi = typeof(IGetContents).GetMethod("GetContents");
+        MyDelegate func = (MyDelegate)mi.CreateDelegate(typeof(MyDelegate));
+
+        (string c1, int c2, string c3) = func(str);
+        if (c1 != "test1")
+            return 1;
+        if (c2 != 42)
+            return 2;
+        if (c3 != "test2")
+            return 3;
+        return 100;
+    }
+}

src/tests/JIT/Regression/JitBlue/Runtime_79354/Runtime_79354.csproj

@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <Optimize>True</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+</Project>

src/tests/issues.targets

@@ -2008,6 +2008,9 @@
         <ExcludeList Include = "$(XunitTestBinBase)/GC/Scenarios/FinalNStruct/finalnstruct/**">
             <Issue>needs triage</Issue>
         </ExcludeList>
+        <ExcludeList Include = "$(XunitTestBinBase)/JIT/Regression/JitBlue/Runtime_79354/Runtime_79354/**">
+            <Issue>https://github.com/dotnet/runtime/issues/57350</Issue>
+        </ExcludeList>
         <ExcludeList Include = "$(XunitTestBinBase)/JIT/Methodical/eh/interactions/strswitchfinal_do/**">
             <Issue>needs triage</Issue>
         </ExcludeList>