Add uniform location checks for ignored/invalid location R=geofflang@chromium.org Bug: chromium:1028418 Change-Id: Iae257fbfa8d58f9a0aa7b876fba416bb060fbe54 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2068127 Commit-Queue: Khushal <khushalsagar@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>