* errno.cc (errmap): Map ERROR_BEGINNING_OF_MEDIA and

ERROR_SETMARK_DETECTED to EIO instead of ESPIPE.
	Handle ERROR_FILEMARK_DETECTED.
	* fhandler_tape.cc (TAPE_FUNC): Add comment that ERROR_BUS_RESET
	has still to be handled correctly.
	(fhandler_dev_tape::open): Accomodate fact that get.mt_dsreg
	also contains density code.
	(fhandler_dev_tape::ioctl): Rearrange slightly.  Reset devbuf also on
	MTNOP, MTWSM, MTSETBLK, MTSETDRVBUFFER, MTSETPART and MTMKPART.
	(fhandler_dev_tape::tape_set_pos): Rearrange.  Match behaviour to
	the Linux tape driver.
	(fhandler_dev_tape::tape_status): Call IOCTL_STORAGE_GET_MEDIA_TYPES_EX
	if available.  Return device type and density code in appropriate
	mtget members.
	* wincap.h (wincaps::has_ioctl_storage_get_media_types_ex): New element.
	* wincap.cc: Implement above element throughout.
	* include/cygwin/mtio.h: Add tape device types as returned by
	IOCTL_STORAGE_GET_MEDIA_TYPES_EX.
	(MT_TAPE_INFO): Use above type codes.
	(struct mtget): Change mt_dsreg comment.

winsup/cygwin/wincap.h

@@ -54,6 +54,7 @@ struct wincaps
   unsigned has_terminal_services			: 1;
   unsigned has_switch_to_thread				: 1;
   unsigned cant_debug_dll_entry				: 1;
+  unsigned has_ioctl_storage_get_media_types_ex		: 1;
 };
 
 class wincapc
@@ -112,6 +113,7 @@ public:
   bool  IMPLEMENT (has_terminal_services)
   bool  IMPLEMENT (has_switch_to_thread)
   bool	IMPLEMENT (cant_debug_dll_entry)
+  bool	IMPLEMENT (has_ioctl_storage_get_media_types_ex)
 
 #undef IMPLEMENT
 };