* fhandler.h (executable_states): For now, make dont_care_if_executable

equivalent to not_executable.
* sys/mount.h: Define MOUNT_NOTEXEC.
* path.h (fs_info): New class.
(path_conv): Move fs-specific fields to new 'fs' structure.
(path_conv::update_fs_info): Move to fs_info and rename to just 'update'.
* path.cc (fs_info::update): Ditto.  Return 'true' if successful.
(fillout_mntent): Add ',noexec' to list of reported options.

winsup/cygwin/fhandler.h

@@ -123,8 +123,8 @@ enum bg_check_types
 enum executable_states
 {
   is_executable,
-  not_executable,
   dont_care_if_executable,
+  not_executable = dont_care_if_executable,
   dont_know_if_executable
 };