util: expand test coverage for util.deprecate

Test for invalid argument types passed to code on util.deprecate.

PR-URL: #16305
Backport-PR-URL: #16430
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

test/parallel/test-util-deprecate-invalid-code.js

@@ -0,0 +1,11 @@
+'use strict';
+
+const common = require('../common');
+const util = require('util');
+
+[1, true, false, null, {}].forEach((notString) => {
+  common.expectsError(() => util.deprecate(() => {}, 'message', notString), {
+    type: TypeError,
+    message: '`code` argument must be a string'
+  });
+});