dotnet-core/release-notes/5.0/netstandard2.1/5.0-preview5_System.Runtime.md

System.Runtime

 namespace System.Runtime {
     public sealed class MemoryFailPoint : CriticalFinalizerObject, IDisposable {
+        ~MemoryFailPoint();
     }
+    public static class ProfileOptimization {
+        public static void SetProfileRoot(string directoryPath);
+        public static void StartProfile(string profile);
+    }
 }