Changes:
  204cd131c Merge pull request #134 from Tobski/patch-1
  e0adad52b Off-by-one errors
  6045738ac Reserve a new block of 64 opcodes

Commands:
  git subtree pull --prefix third_party/SPIRV-Headers https://github.com/KhronosGroup/SPIRV-Headers master --squash

Bug: b/123642959
Change-Id: I9389ad9ea7916464745c2dfedefe46e3ef3a52e4