dotnet-core/release-notes/3.0/api-diff/3.0.0_System.Runtime.md

System.Runtime

 namespace System.Runtime {
+    public sealed class AmbiguousImplementationException : Exception {
+        public AmbiguousImplementationException();
+        public AmbiguousImplementationException(string message);
+        public AmbiguousImplementationException(string message, Exception innerException);
+    }
+    public static class ProfileOptimization {
+        public static void SetProfileRoot(string directoryPath);
+        public static void StartProfile(string profile);
+    }
 }