(Below you’ll find some pretty significant spoilers for the premiere of Marvel series “Loki” on Disney+. So, if you haven’t watched the episode yet, you might want to steer. Unless you like spoilers, in which case have fun!) There are plenty of things on “Loki” that will make your head hurt if you think about them too hard. We’ve got time travel and multiverses and time cops and just generally a whole bunch of outlandish sci-fi things. And we’ve also got Infinity Stones. A lot of Infinity Stones. The Stones pop up while Loki makes a brief attempt to escape the clutches of the . . .