Fix assembly resolution for System.Security.AccessControl

src/Compilers/Core/MSBuildTask/AssemblyResolution.cs

@@ -54,6 +54,7 @@ private static bool TryRedirect(AssemblyName name)
                     return TryRedirect(name, s_b03f5f7f11d50a3a, 4, 0, 2, 0);
 
                 case "System.Diagnostics.StackTrace":
+                case "System.Security.AccessControl":
                     return TryRedirect(name, s_b03f5f7f11d50a3a, 4, 0, 3, 0);
 
             }

src/Compilers/Core/MSBuildTask/ValidateBootstrap.cs

@@ -92,9 +92,16 @@ private static string NormalizePath(string path)
 
         internal static void AddFailedLoad(AssemblyName name)
         {
-            if (Path.GetExtension(name.Name) != ".resources")
+            switch (name.Name)
             {
-                s_failedLoadSet.TryAdd(name, 0);
+                case "System":
+                case "System.Core":
+                case "Microsoft.Build.Tasks.CodeAnalysis.resources":
+                    // These are failures are expected by design.
+                    break;
+                default:
+                    s_failedLoadSet.TryAdd(name, 0);
+                    break;
             }
         }
     }