Replace wrapper shell script with wrapper hack script

Author: fredemmott

bin/hh-codegen-verify-signatures

@@ -1,2 +1,17 @@
-#!/bin/sh
-exec "$0.hack" "$@"
+#!/usr/bin/env hhvm
+/*
+ *  Copyright (c) 2015-present, Facebook, Inc.
+ *  All rights reserved.
+ *
+ *  This source code is licensed under the MIT license found in the
+ *  LICENSE file in the root directory of this source tree.
+ *
+ */
+
+namespace Facebook\HackCodegen;
+
+<<__EntryPoint>>
+function verify_signatures_main_UNSAFE(): noreturn {
+  require_once(__FILE__.'.hack');
+  verify_signatures_main();
+}