src: Replace macros with util functions

lib/console.js

@@ -25,7 +25,7 @@ function Console(stdout, stderr) {
   if (!(this instanceof Console)) {
     return new Console(stdout, stderr);
   }
-  if (!stdout || !IS_FUNCTION(stdout.write)) {
+  if (!stdout || !util.isFunction(stdout.write)) {
     throw new TypeError('Console expects a writable stream instance');
   }
   if (!stderr) {