* configure.in (AC_CHECK_FUNCS): Add setpggrp.

* configure.in (AC_CHECK_FUNCS): Add setpggrp.
(AC_FUNC_SETPGRP): Add.
* aclocal.m4, configure, config.in: Regenerated.
* inflow.c (gdb_setpgid): Get rid of NEED_POSIX_SETPGID and
SETPGRP_ARGS.  Always use setpgid if it is available, fall back on
setpgrp if it isn't.  Use SETPGRP_VOID (defined by autoconf) to
distinguish between the two setpgrp flavours.
* config/xm-sysv4.h, config/arm/xm-linux.h,
config/i386/xm-i386aix.h, config/i386/xm-sco.h,
config/i386/xm-linux.h, config/i386/xm-ptx.h,
config/m68k/xm-linux.h, config/powerpc/xm-linux.h,
config/sparc/xm-linux.h, config/sparc/xm-sun4sol2.h,
config/ia64/xm-linux.h (NEED_POSIX_SETPGID): Remove.
* config/rs6000/xm-rs6000.h (SETPGRP_ARGS): Remove.