Suppress self-assign warning in angle_deqp_decpp and angle_deqp_libtester Compiling dEQP with clang started failing after clang roll https://chromium-review.googlesource.com/1012028 BUG=chromium:832753 Change-Id: I532872a68c3c8d916c6bfd2b5370501746076193 Reviewed-on: https://chromium-review.googlesource.com/1012382 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Yuly Novikov <ynovikov@chromium.org>