[linker] Remove new memory allocations (List) in the sealer

tools/linker/MonoTouch.Tuner/SealerSubStep.cs

@@ -1,7 +1,6 @@
 // Copyright 2016 Xamarin Inc. All rights reserved.
 
 using System;
-using System.Linq;
 using System.Collections.Generic;
 using Mono.Cecil;
 using Mono.Linker;
@@ -85,7 +84,7 @@ namespace Xamarin.Linker.Steps {
 					// sanity (disable IsSealed == true above)
 					//if (type.IsSealed)
 					//	Console.WriteLine ();
-					if (AreMarked (overrides.Select (x => x.Override).ToList ()))
+					if (AreMarked (overrides))
 						continue;
 				}
 
@@ -110,6 +109,17 @@ namespace Xamarin.Linker.Steps {
 			}
 		}
 
+		bool AreMarked (List<OverrideInformation> list)
+		{
+			if (list == null)
+				return false;
+			foreach (var m in list) {
+				if (Annotations.IsMarked (m.Override))
+					return true;
+			}
+			return false;
+		}
+
 		bool AreMarked (List<MethodDefinition> list)
 		{
 			if (list == null)