merge: change repo.wvfs.setflags calls to a new wctx[f].setflags function

As with previous changes in this series, this should be a no-op.

mercurial/context.py

@@ -1896,6 +1896,9 b' class workingfilectx(committablefilectx)'
         """wraps repo.wwrite"""
         self._repo.wwrite(self._path, data, flags)
 
+    def setflags(self, l, x):
+        self._repo.wvfs.setflags(self._path, l, x)
+
 class workingcommitctx(workingctx):
     """A workingcommitctx object makes access to data related to
     the revision being committed convenient.

mercurial/merge.py

@@ -1291,7 +1291,7 b' def applyupdates(repo, actions, wctx, mc'
         progress(_updating, z, item=f, total=numupdates, unit=_files)
         flags, = args
         audit(f)
-        repo.wvfs.setflags(f, 'l' in flags, 'x' in flags)
+        wctx[f].setflags('l' in flags, 'x' in flags)
         updated += 1
 
     # the ordering is important here -- ms.mergedriver will raise if the merge