status: cache dirstate status in _dirstatestatus()

Since it's only the dirstate status we cache, it makes more sense to
cache it in the _dirstatestatus() method. Note that this change means
the dirstate status will also be cached when status is requested
between the working copy and some other revision, while we currently
only cache the result if exactly the status between the working copy
and its parent is requested.

mercurial/context.py

@@ -1495,6 +1495,15 b' class workingctx(committablectx):'
             if fixup and listclean:
                 s.clean.extend(fixup)
 
+        if match.always():
+            # cache for performance
+            if s.unknown or s.ignored or s.clean:
+                # "_status" is cached with list*=False in the normal route
+                self._status = scmutil.status(s.modified, s.added, s.removed,
+                                              s.deleted, [], [], [])
+            else:
+                self._status = s
+
         return s
 
     def _buildstatus(self, other, s, match, listignored, listclean,
@@ -1515,14 +1524,6 b' class workingctx(committablectx):'
             s = super(workingctx, self)._buildstatus(other, s, match,
                                                      listignored, listclean,
                                                      listunknown)
-        elif match.always():
-            # cache for performance
-            if s.unknown or s.ignored or s.clean:
-                # "_status" is cached with list*=False in the normal route
-                self._status = scmutil.status(s.modified, s.added, s.removed,
-                                              s.deleted, [], [], [])
-            else:
-                self._status = s
         return s
 
     def _matchstatus(self, other, match):