Makes a lot common between Linux and Windows using git bash.

Bug: angleproject:4620
Change-Id: I68cf8ac0fb43bc9c21d07ae3abecf5ca0358261c
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2189814
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Cody Northrop <cnorthrop@google.com>