When Willie released “Roll Me Up and Smoke Me When I Die” as a single on, of course, April 20, 2012, it became an instant fan favorite, and there are a host of reasons why. For one, it’s a great mix of three Willie hallmarks, namely a catchy melody, his insouciant wit, and weed, and concertgoers have been waving joints overhead when he plays it ever since. On the record, it’s a bright-line example of the wide net he’s always cast when it comes to collaborators: a Highwaymen-esque partnering with Kris Kristofferson, Jamey Johnson . . . and Snoop Dogg. And then, for the real-deal Willie nerds who notice Buddy Cannon’s name among the co-writers, it’s a pivotal entry in his songwriting catalog, a crucial first step into the…