Add test for eventhandler

Tests/Kernels/Cosmos.Compiler.Tests.Bcl/Kernel.cs

@@ -37,6 +37,7 @@ namespace Cosmos.Compiler.Tests.Bcl
                 BitConverterTest.Execute();
                 UnsafeCodeTest.Execute();
                 DelegatesTest.Execute();
+                EventsTest.Execute();
                 RandomTests.Execute();
 
                 // System.Collections

Tests/Kernels/Cosmos.Compiler.Tests.Bcl/System/EventsTest.cs

@@ -0,0 +1,36 @@
+using System;
+using Cosmos.TestRunner;
+
+namespace Cosmos.Compiler.Tests.Bcl.System
+{
+    internal class TestClass
+    {
+        private static bool handlerInvoked;
+
+        public event EventHandler EventFired = (sender, args) =>
+        {
+            handlerInvoked = true;
+        };
+
+        private void OnEventFired(EventArgs e)
+        {
+            EventHandler handler = EventFired;
+            handler?.Invoke(this, e);
+        }
+
+        public bool ExecuteTest()
+        {
+            OnEventFired(null);
+            return handlerInvoked;
+        }
+    }
+
+    public class EventsTest
+    {
+        public static void Execute()
+        {
+            var test = new TestClass();
+            Assert.IsTrue(test.ExecuteTest(), "Event handler was not invoked.");
+        }
+    }
+}