status: explicitly exclude removed file from unknown and ignored

Changeset 64fe488b5179 introduced a test to validate that file were not reported
twice when both unknown and removed. This behavior change was introduced by
65cdc6bab91e alongside a bug that dropped ignored and unknown completely
(issue4321). As we are going to fix the bug, we need a proper implementation of
the behavior tested in 64fe488b5179.

mercurial/context.py

@@ -135,6 +135,10 b' class basectx(object):'
             elif fn not in deleted:
                 added.append(fn)
         removed = mf1.keys()
+        if removed:
+            # need to filter files if they are already reported as removed
+            unknown = [fn for fn in unknown if fn not in mf1]
+            ignored = [fn for fn in ignored if fn not in mf1]
 
         return [modified, added, removed, deleted, unknown, ignored, clean]