Manually roll spirv-headers
Manually roll spirv-headers

https://chromium.googlesource.com/external/github.com/KhronosGroup/SPIRV-Headers.git/+log/af64a9e826bf..dc77030acc9c

The spirv-tools autoroller didn't roll this repo.

Bug: chromium:1044061
Change-Id: I5ad841e1957d48506f6b3c4a1a57e003b35b6f24
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2014882
Reviewed-by: Tim Van Patten <c7814369a8d3d5671c484acc7b3215f1bf4221be@google.com>
Commit-Queue: Shahbaz Youssefi <582eeec4f08a2ccd61e3ef52115e6e7c571582de@chromium.org>

ppy/angle,ppy/angle,ppy/angle,ppy/angle