* path.h (etc::change_possible): Revert the type to bool.

(etc::set_last_modified): Remove obsolete function.
* path.cc (etc::change_possible): Revert type to bool.
(etc::test_file_change): Do not test for negative values of change_possible and
do not set it to -res.
(etc::dir_changed): When the handle is NULL, call memset instead of
test_file_changed.  When the handle is invalid, return true.
(etc::file_changed): Remove unneeded check for !fn[n].

winsup/cygwin/pwdgrp.h

@@ -59,7 +59,6 @@ public:
       state = initializing;
     return state == initializing;
   }
-  void operator = (pwdgrp_state nstate) { state = nstate; }
   bool isuninitialized () const { return state == uninitialized; }
 
   bool load (const char *);