Summary:
Our linters assume that clang-format is installed at /mnt/vol/engshare/admin/scripts/clang-format and flint is installed at /home/engshare/tools/flint. This makes them fail on non-fb machines. This change will:
* if clang-format is not on a specified path, it will try running generic clang-format. Linters will still fail if clang-format is not installed, but this shouldn't be a big issue, since it's pretty easy to install it.
* flint will not be run if /home/engshare/tools/flint is not present
Test Plan: Made a change on a mac machine. Ran `arc lint`. No failures observed.
Reviewers: aekmekji, yhchiang
Reviewed By: yhchiang
Subscribers: dhruba, leveldb
Differential Revision: https://reviews.facebook.net/D44031
a03085b556