Check for misconfiguration of shader built-ins Fail compiler initialization if the built-in resources are invalid. This avoids creating zero-sized arrays out of built-ins into the symbol table, which could later lead to asserts when these built-ins were indexed by constants. BUG=chromium:667468 TEST=angle_unittests Change-Id: I9553c7c91ea355abb35b9cc6088ee14b40b0922b Reviewed-on: https://chromium-review.googlesource.com/413037 Commit-Queue: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org>