Running 'python3 update.py windows' from 'third_party/llvm-7.0/scripts/'

Bug chromium:944811

Change-Id: I4cd1a51b2c50f775d3131d5c66b1d33350b8004b
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/27870Reviewed-by: Alexis Hétu <sugoi@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>