fix: include original exception stacktrace when calling a method from a c# object from lua side

Author: acoppes

src/MoonSharp.Interpreter.Tests/EndToEnd/ErrorHandlingTests.cs

@@ -154,5 +154,36 @@ public void Errors_Get_OriginalException()
 			}
 		}
 
+		private class ClassWithMember
+		{
+			public void MethodWithError()
+			{
+				throw new NullReferenceException();
+			}
+		}
+		
+		[Test]
+		public void Errors_Get_OriginalException_WhenUsingMember()
+		{
+			string luaScript = 
+				@"
+	objectWithMethod.MethodWithError();
+";
+			Script script = new Script(CoreModules.None);
+			
+			UserData.RegisterType<ClassWithMember>();
+
+			script.Globals["objectWithMethod"] = new ClassWithMember();
+
+			try
+			{
+				script.DoString(luaScript);
+			}
+			catch (Exception e)
+			{
+				Assert.IsTrue(e.StackTrace.Contains("MoonSharp.Interpreter.Tests.EndToEnd.ErrorHandlingTests.ClassWithMember.MethodWithError() "), "Exception should contain c# error line");
+			}
+		}
+
 	}
 }

src/MoonSharp.Interpreter/Interop/StandardDescriptors/ReflectionMemberDescriptors/MethodMemberDescriptor.cs

@@ -212,9 +212,9 @@ public override DynValue Execute(Script script, object obj, ScriptExecutionConte
 
 				return BuildReturnValue(script, outParams, pars, retv);
 			}
-			catch (Exception e)
+			catch
 			{
-				throw e;
+				throw;
 			}
 		}