translator: Reject invalid combination of compile flags ADD_AND_TRUE_TO_LOOP_CONDITION breaks loop unrolling because LoopInfo expects the loop condition to have been validated to be "symbol < constant" and stayed that way. BUG=chromium:653454 BUG=chromium:653694 Change-Id: I2057fde3a308623bd2dd7571ee878dd42b1fdac3 Reviewed-on: https://chromium-review.googlesource.com/395306 Reviewed-by: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Corentin Wallez <cwallez@chromium.org>