test: fix test-repl-tab-complete after V8 upgrade

Array#includes is now available.

PR-URL: nodejs#3481
Reviewed-By: targos - Michaël Zasso <mic.besace@gmail.com>

Author: ofrobots

test/parallel/test-repl-tab-complete.js

@@ -273,6 +273,7 @@ var array_elements = [ [
   'ary.find',
   'ary.findIndex',
   'ary.forEach',
+  'ary.includes',
   'ary.indexOf',
   'ary.join',
   'ary.keys',