Alright, I figured it out. I don't have to create an swc file. I just have to create a folder structure that matches the package name (com-esri-ags-samples) and then put the .as file in the samples folder. Then, when I run mxmlc on the mxml file, it creates the swf!! yay!
I guess the question would now be, would you ever create an swc file for an extended class?