run buildifier on unified build files (#98141)
This is pretty tricky. buildifier by default doesn't do much to these
files. It does a little more if you tell it that they are
`BUILD.bazel` files with -type=build. But it can do even more if you
remove the target definitions from the `def define_rules()` wrapper
and dedent them.
I wrote a little wrapper that does that. I'll submit it at a later
date.
Differential Revision: [D44606558](https://our.internmc.facebook.com/intern/diff/D44606558/)
**NOTE FOR REVIEWERS**: This PR has internal Meta-specific changes or comments, please review them on [Phabricator](https://our.internmc.facebook.com/intern/diff/D44606558/)!
Pull Request resolved: https://github.com/pytorch/pytorch/pull/98141
Approved by: https://github.com/ezyang, https://github.com/PaliC
