X: Exene Cervenka, Billy Zoom, Jon Doe, and D.J. Bonebrake, pictured sometime well in advance of their current 31st anniversary tour. As unabashedly retro, amphetamine-spiked rocksoulpunkabilly two-fers go, you’d be hard-pressed to do better than pioneering Los Angeles punkers X, with garage-rock archeologists the Detroit Cobras on the undercard. Billed as X’s 31st anniversary tour, (though their recorded career began with 1980’s Los Angeles) this greasy double bill pulled into the 9:30 Club Wednesday…