kernel: Fix == to ===.

support/kernel-language.js

@@ -267,7 +267,7 @@ define(['./compatibility'], function () {
         st.addClass = function (className, superclass, iVarNames, pkgName) {
             // While subclassing nil is allowed, it might be an error, so
             // warn about it.
-            if (typeof superclass == 'undefined' || superclass && superclass.a$nil) {
+            if (typeof superclass === 'undefined' || superclass && superclass.a$nil) {
                 console.warn('Compiling ' + className + ' as a subclass of `nil`. A dependency might be missing.');
             }
             return buildBehaviorBody(pkgName, classBuilder(className, superclass, iVarNames, coreFns[className]));