* fork-child.c (startup_inferior) [STARTUP_INFERIOR]: If defined,

	* fork-child.c (startup_inferior) [STARTUP_INFERIOR]: If defined,
	call it instead of doing normal loop.
	* infcmd.c (attach_command): Don't call wait_for_inferior if
	running	Mach 3.
	* infrun.c (proceed) [PREPARE_TO_PROCEED]: If defined, call
	hook that can decide whether to step over the next breakpoint.
	* utils.c (wrap_here): Abort if wrap_buffer not allocated.
	(request_quit) [REQUEST_QUIT]: If defined, call it instead of
	doing normal quit.

	* Makefile.in (stop-gdb): New target.
	* stop-gdb.c: New file, utility to get attention of waiting GDBs
	in Mach 3.