py3: port ext-phase-report.py extension

The custom module importer doesn't run on Python files in the
tests directory. So we need the source to be compatible with
both Python 2 and 3.

Differential Revision: https://phab.mercurial-scm.org/D2145

tests/testlib/ext-phase-report.py

@@ -5,18 +5,18 b' from __future__ import absolute_import'
 def reposetup(ui, repo):
 
     def reportphasemove(tr):
-        for rev, move in sorted(tr.changes['phases'].iteritems()):
+        for rev, move in sorted(tr.changes[b'phases'].items()):
             if move[0] is None:
-                ui.write(('test-debug-phase: new rev %d:  x -> %d\n'
+                ui.write((b'test-debug-phase: new rev %d:  x -> %d\n'
                           % (rev, move[1])))
             else:
-                ui.write(('test-debug-phase: move rev %d: %s -> %d\n'
+                ui.write((b'test-debug-phase: move rev %d: %d -> %d\n'
                           % (rev, move[0], move[1])))
 
     class reportphaserepo(repo.__class__):
         def transaction(self, *args, **kwargs):
             tr = super(reportphaserepo, self).transaction(*args, **kwargs)
-            tr.addpostclose('report-phase', reportphasemove)
+            tr.addpostclose(b'report-phase', reportphasemove)
             return tr
 
     repo.__class__ = reportphaserepo