Use reference comments again.

tests/cases/compiler/noDefaultLib.ts

@@ -1,4 +1,4 @@
-// @noLib: true
+/// <reference no-default-lib="true"/>
 var x;
 
 interface Array {}

tests/cases/compiler/typeCheckTypeArgument.ts

@@ -1,4 +1,4 @@
-// @noLib: true
+/// <reference no-default-lib="true"/>
 
 var f: <T extends UNKNOWN>() => void;
 

tests/cases/conformance/decorators/1.0lib-noErrors.ts

@@ -1,5 +1,4 @@
 // @target: ES5
-// @noLib: true
 /* *****************************************************************************
 Copyright (c) Microsoft Corporation. All rights reserved. 
 Licensed under the Apache License, Version 2.0 (the "License"); you may not use