Add test

src/coreclr/tools/ILTrim/ILTrim.Tests.Cases/Basic/ExceptionRegions.cs

@@ -0,0 +1,52 @@
+// 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 Mono.Linker.Tests.Cases.Expectations.Assertions;
+
+namespace Mono.Linker.Tests.Cases.Basic
+{
+    [Kept]
+    public class ExceptionRegions
+    {
+        [Kept]
+        static void Main()
+        {
+            try
+            {
+                A();
+            }
+            catch (CustomException ce)
+            {
+                Console.WriteLine(ce.Message);
+                try
+                {
+                    B();
+                }
+                catch (Exception e) when (e.InnerException != null)
+                {
+                    Console.WriteLine(e.Message);
+                }
+            }
+            finally
+            {
+                C();
+            }
+        }
+
+        [Kept]
+        static void A() { }
+
+        [Kept]
+        static void B() { }
+
+        [Kept]
+        static void C() { }
+    }
+
+    [Kept]
+    [KeptBaseType(typeof(Exception))]
+    class CustomException : Exception
+    {
+    }
+}