Fix atomicAdd validation w.r.t to swizzles Bug: angleproject:4150 Change-Id: I22c0c0382a2b208dd983fa1981ffc75f1b1945e9 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2022359 Reviewed-by: Ian Elliott <ianelliott@google.com> Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>