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

Array#includes is now available.

Ref: https://github.com/nodejs/node/pull/3481
PR-URL: https://github.com/nodejs/node/pull/4106
Reviewed-By: bnoordhuis - Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: targos - Michaël Zasso <mic.besace@gmail.com>
Reviewed-By: rvagg - Rod Vagg <rod@vagg.org>

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

@@ -258,6 +258,7 @@ var array_elements = [ [
   'ary.find',
   'ary.findIndex',
   'ary.forEach',
+  'ary.includes',
   'ary.indexOf',
   'ary.join',
   'ary.keys',