[loop] and [flatten] help avoid unrolling make more shaders compile successfully. When unrolling has to happen, an error X3531 is generated so we have to try compiling again without these attributes. BUG=395048,395286 Change-Id: I91ea8ac3a822ab1f1ac24907d42326e3c6c9d9af Reviewed-on: https://chromium-review.googlesource.com/222810Tested-by: Nicolas Capens <capn@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>
