After Reading a couple of question on how to upgrade xampp to newer versions of php. I started upgrading mine to version 7 as I wanted to learn
strict type hinting
Not sure if you were able to resolve this, but figured I'd suggest an approach since this question comes up high in Google searches and might benefit others.
Apache Friends released a version of XAMPP for Windows, Linux, and OS that supports PHP 7.0.1.
From the site:
We just released a new version of XAMPP for all platforms with PHP 7.0.1. This version also includes a fixed version of the setup_xampp.bat and test_php.bat scripts for Windows.
It can be downloaded from Apache Friends.