builtin.

If syntactically invalid job identifiers are to be taken as jobs that exited
with status 127, this should not apply to options, so that we can add
options later if need be.

This has always been the case and is intended (just like cd).

This matches Austin group issue #706.

In some other shells, things like $((a);(b)) are command substitutions.

Also, there are shells that have an extension ((ARITH)) that evaluates an
arithmetic expression and returns status 1 if the result is zero, 0
otherwise. This extension may lead to ambiguity with two subshells starting
in sequence.

 * Work around kernel bugs that cause a spurious [EINTR] return if a
   debugger (such as truss(1)) is attached.

 * Write an error message if an error other than [EINTR] occurs.

PR:		bin/178664

Update chio(1) and ch(4) to support reporting element designators.

This allows mapping a tape drive in a changer (as reported by
'chio status') to a sa(4) driver instance by comparing the
serial numbers.

The designators can be ASCII (which is printed out directly), binary
(which is printed in hex format) or UTF-8, which is printed in either
native UTF-8 format if the terminal can support it, or in %XX notation
for non-ASCII characters.  Thanks to Hiroki Sato <hrs@> for the
explanation and example UTF-8 printing code.

chio.h:		Modify the changer_element_status structure to add new
		fields and definitions from the SMC3r16 spec.

		Rename the original CHIOGSTATUS ioctl to OCHIOGTATUS and
		define a new CHIOGSTATUS ioctl.

		Clean up some tab/space issues.

chio.c: 	For the 'status' subcommand, print the designator field
		if it is supplied by a device.

scsi_ch.h:	Add new flags for DVCID and CURDATA to the READ
		ELEMENT STATUS command structure.

		Add a read_element_status_device_id structure
		for the data fields in the new standard. Add new
		unions, dt_or_obsolete and voltage_devid, to hold
		and address data from either SCSI-2 or newer devices.

scsi_ch.c:	Implement support for fetching device IDs with READ
		ELEMENT STATUS data.

		Add new arguments to scsi_read_element_status() to
		allow the user to request the DVCID and CURDATA bits.
		This isn't compiled into libcam (it's only an internal
		kernel interface), so we don't need any special
		handling for the API change.

		If the user issues the new CHIOGSTATUS ioctl, copy all of
		the available element status data out.  If he issues the
		OCHIOGSTATUS ioctl, we don't copy the new fields in the
		structure.

		Fix a bug in chopen() that would result in the peripheral
		never getting unheld if chgetparams() failed.

Sponsored by:	Spectra Logic
Submitted by:	Po-Li Soong

Constify parameters, no functional or binary change.