Pastel 1.0 does not need to implement logic ops. From discussion with
capn@, the existing support was only ever partial, and covered the exact
needs of a special project.

Change-Id: I3003227c4d29ab5d39e0ae6385207c87d22931e2
Reviewed-on: https://swiftshader-review.googlesource.com/c/25828Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Chris Forbes <chrisforbes@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>