Summary:
Pull Request resolved: https://github.com/facebook/yoga/pull/1781
This new image removed preinstalled libc++, and the ability to install old version of Clang Format we were installing.
This manually installs libc++ when setting up Clang jobs, and fully removes the clang-format validation job, since it wasn't correctly running before, and it's probably more a pain to ask people to run this than to just run Arcanist when importing a change.
Changelog: [Internal]
Reviewed By: joevilches
Differential Revision: D68455129
fbshipit-source-id: b5767be832b2b5d46db7e60e18b66823819ba15a