Add crosjobs shim script

BUG=chromium:973247

Change-Id: Ibbc10cbefb85b5c9ab7a8092d1ac8d4a16af9e32
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1745892Reviewed-by: Robbie Iannucci <iannucci@chromium.org>
Commit-Queue: Yaakov Shaul <yshaul@chromium.org>

crosjobs

+#!/usr/bin/env bash
+
+# Copyright 2018 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+MYPATH=$(dirname "${BASH_SOURCE[0]}")
+
+source "$MYPATH/cipd_bin_setup.sh"
+cipd_bin_setup &> /dev/null
+
+exec "$MYPATH/.cipd_bin/buildjobs" "$@"
+