Add a document 'How to Write Tests Using FileCheck' (#19005)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/19005
ghimport-source-id: f9c3eff54adc8eef3ead2c77be62c44d88d22a00
Differential Revision: D14826845
Pulled By: ZolotukhinM
fbshipit-source-id: 62cc3657ee89acc979403da15e39bd4cd09a866d
Author
Mikhail Zolotukhin
