transaction: drop special handling for phases and bookmarks generation

We are still doing double backups, but now that we have proper
location handling this is less of an issue. Dropping this simplifies
the code before we add some pending-related logic.

This also ensures we actually test the new 'location' mechanism.

mercurial/transaction.py

@@ -270,11 +270,7 b' class transaction(object):'
             files = []
             try:
                 for name in filenames:
-                    # Some files are already backed up when creating the
-                    # localrepo. Until this is properly fixed we disable the
-                    # backup for them.
-                    if name not in ('phaseroots', 'bookmarks'):
-                        self.addbackup(name, location=location)
+                    self.addbackup(name, location=location)
                     files.append(vfs(name, 'w', atomictemp=True))
                 genfunc(*files)
             finally: