Throughout replace all usage of wincap.shared with the constant

FILE_SHARE_VALID_FLAGS.
	* fhandler.cc (fhandler_base::open_9x): Drop local variable shared.
	* wincap.cc: Remove shared member throughout.
	* wincap.h: Ditto.

winsup/cygwin/path.cc

@@ -4283,7 +4283,8 @@ cwdstuff::set (const char *win32_cwd, const char *posix_cwd, bool doit)
 	      if (wincap.can_open_directories ())
 		{
 		  HANDLE h = CreateFile (win32_cwd, FILE_TRAVERSE,
-					 wincap.shared (), NULL, OPEN_EXISTING,
+					 FILE_SHARE_VALID_FLAGS, NULL,
+					 OPEN_EXISTING,
 					 FILE_FLAG_BACKUP_SEMANTICS, NULL);
 		  if (h == INVALID_HANDLE_VALUE)
 		    {