Add failing test (parameter count mismatch)

Methods compiled from expression trees can have an additional first
parameter of type `Sytem.Runtime.CompilerServices.Closure` which
apparently captures all closed-over variables.

This additional parameter can trigger a parameter count mismatch error
in `MethodCallReturn.ValidateNumberOfCallbackParameters`.

The test code is taken from:
devlooped#652 (comment)

tests/Moq.Tests/Regressions/IssueReportsFixture.cs

@@ -1974,6 +1974,39 @@ public void Struct_ByRef_Delegate()
 
  #endregion
 
+ #region 652
+
+ public class Issue652
+ {
+ [Fact]
+ public void Callback_delegates_compiled_from_Expression_are_usable_despite_additional_hidden_Closure_parameter()
+ {
+ Mock<IMyInterface> mock = new Moq.Mock<IMyInterface>();
+ var setupAction = mock.Setup(my => my.MyAction(It.IsAny<int>()));
+ var setupFunc = mock.Setup(my => my.MyFunc(It.IsAny<int>()));
+
+ int a = 5;
+ Expression<Action<int>> callback = x => Console.WriteLine(a);
+ Action<int> callbackCompiled = callback.Compile();
+
+ int b = 4;
+ Expression<Func<int, int>> funcResult = x => b;
+ Func<int, int> funcResultCompiled = funcResult.Compile();
+
+ setupAction.Callback(callbackCompiled); // OK
+ setupFunc.Callback(callbackCompiled); // OK
+ setupFunc.Returns(funcResultCompiled); // Fail
+ }
+
+ public interface IMyInterface
+ {
+ void MyAction(int x);
+ int MyFunc(int x);
+ }
+ }
+
+ #endregion
+
  // Old @ Google Code
 
  #region #47