This makes them runnable directly on Linux.

Bug: angleproject:5134
Change-Id: Icf5ccf9d82b8cf09b16c5c60312e33752a9724e4
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2495288
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Cody Northrop <cnorthrop@google.com>