standards/187378: stdlib.h doesn't define W* macros (e.g. WEXITSTATUS)

[Garrett Wollman]

<<On Wed, 12 Mar 2014 04:30:55 +1100 (EST), Bruce Evans <brde at optusnet.com.au> said:

> This was a bug in XSI.  You can't even use these macros without doing
> something nonstandard to get a value that they apply too.

> Unfortunately, the infestation has now spread to POSIX itself -- this is
> now shaded CX instead of XSI in the above URL.

See RETURN VALUE for system() at XSHv7 page 2069:

	If command is not a null pointer, system ( ) shall return the
	termination status of the command language interpreter in the
	format specified by waitpid ( ). The termination status shall
	be as defined for the sh utility; otherwise, the termination
	status is unspecified. If some error prevents the command
	language interpreter from executing after the child process is
	created, the return value from system ( ) shall be as if the
	command language interpreter had terminated using exit(127) or
	_exit(127). If a child process cannot be created, or if the
	termination status for the command language interpreter cannot
	be obtained, system ( ) shall return -1 and set errno to
	indicate the error.

This paragraph is also shaded CX, not XSI, and was CX in XSHv6 (at
p. 1474).

-GAWollman