This review of “Lux Aeterna” was first published on May 20, 2019, after its premiere at the Cannes Film Festival.Cinematic provocateurs have flourished at the Cannes Film Festival for years, with everyone from Jean-Luc Godard to Lars von Trier coming to the Croisette with works designed to provoke, confront or even annoy an audience. At this year’s festival, you could say that some of the extreme sections of Nicolas Winding Refn’s “Too Old to Die Young” have been designed to test an audience’s limits and make viewers uncomfortable.But nobody does provocation these days quite like Gaspar Noe does.