Missing _sigmask in Battlestar

[yee at ucbvax.ARPA]

Several people have let me know that sigmask is not defined in Battlestar.
The problem is that sigmask is a macro which is found in version 6.2 of
signal.h, and not in previous versions.  Following this is the definition
of sigmask.  Just add it to the files which reference sigmask, and the
problems should be cleared up.

						-Peter Yee
						..ucbvax!yee
						yee at Berkeley.ARPA


/*
 * Macro for converting signal number to a mask suitable for
 * sigblock().
 */
#define sigmask(m)	(1 << ((m)-1))