changegroup: combine _generatefiles() into generatefiles() These were split out in a06aab274aef as part of moving the narrow code into core. They don't need to be separate functions. Differential Revision: https://phab.mercurial-scm.org/D4192

changegroup: define linknodes callbacks in generatefiles() This is how it is done everywhere else. But the logic here is a bit more complex because shallow clone needs to reference the original linknode implementation. But at least now all function implementations are defined in the same place. Differential Revision: https://phab.mercurial-scm.org/D4191