Even if you’re not a fan of Robert Rodriguez’s footloose and fancy-free style of maverick filmmaking, you have to respect the fact that he certainly knows how to round up an impressive cast with each passing film. While he usually peppers films from “Spy Kids” to “Sin City” and beyond with delightful and unexpected casting choices, “Machete Kills” serves to be no exception to the rule. We already have Danny Trejo returning as the titular character, with roles for Zoe Saldana, Amber Heard, Michelle Rodriguez, Jessica Alba, and Sofia Vergara. Rodriguez has also thrown in Academy Award-nominated actor Demian Bichir and (reportedly) “Ong Bak” martial artist Tony Jaa for us cinefiles, and then there’s potentially volatile concoction of stars Mel Gibson as the film’s villain and Charlie Sheen playing THE PRESIDENT OF THE UNITED STATES. Yikes, Rodriguez surely knows how to cause a stir.