basectx: move _dirs from changectx

mercurial/context.py

@@ -138,6 +138,10 b' class basectx(object):'
         return patch.diff(self._repo, ctx2.node(), self.node(),
                           match=match, opts=diffopts)
 
+    @propertycache
+    def _dirs(self):
+        return scmutil.dirs(self._manifest)
+
 class changectx(basectx):
     """A changecontext object makes access to data related to a particular
     changeset convenient. It represents a read-only context already presnt in
@@ -399,10 +403,6 b' class changectx(basectx):'
             if match.bad(fn, _('no such file in rev %s') % self) and match(fn):
                 yield fn
 
-    @propertycache
-    def _dirs(self):
-        return scmutil.dirs(self._manifest)
-
     def dirs(self):
         return self._dirs