* fork-child.c (fork_inferior): Only reset the thread list if this

	* fork-child.c (fork_inferior): Only reset the thread list if this
	is the first inferior.
	(startup_inferior): If the target support multi-process, tell it
	to resume only the new process.
	* linux-nat.c (num_lwps): Delete global.
	(purge_lwp_list): New function.
	(num_lwps): New function.
	(add_lwp, delete_lwp): Adjust.
	(ptid_match): New.
	(iterate_over_lwps): Add filter argument.  Handle it.
	(linux_nat_attach): Remove FIXME note.
	(linux_nat_detach): Adjust to iterate over threads of the inferior
	we're detaching from.  Adjust to num_lwps being a function.  Don't
	assume the head of the lwp list is the main thread of the process
	we're detaching from.  Don't destroy the LWP list.
	(resume_callback): Add debug output.
	(linux_nat_resume): Handle resuming a single inferior.  Allow a
	wildcard resume in non-stop mode.
	(linux_handle_extended_wait): Don't assume inferior_ptid is the
	correct inferior of the parent LWP.
	(status_callback): Also check lp->waitstatus.
	(select_event_lwp): Add new filter parameter.  Handle it.
	(linux_nat_filter_event): Adjust to num_lwps being a function.
	(linux_nat_wait_1): When adding the first lwp of the inferior, use
	an is_lwp check instead of checking for the number of lwps.
	(linux_nat_wait_1): Handle waiting for a specific tgid.  Handle
	pending process exit statuses.
	(linux_nat_mourn_inferior): Don't destroy all the LWP info.
	Instead delete LWPs of the inferior that we're mourning.  Don't
	unregister from the event loop here.
	(linux_nat_pid_to_str): Use `num_lwps'.
	(linux_nat_make_corefile_notes): Adjust to walk over lwps of a
	single inferior.
	(linux_nat_is_async_p): Check if async was masked out.
	(linux_multi_process): New global.
	(linux_nat_supports_multi_process): New.
	(linux_nat_stop_lwp): Remove LWP filtering.  It is done by the
	caller.
	(linux_nat_stop): Adjust to make iterate_over_lwps itself do the
	LWP filtering.
	(linux_nat_close): New.
	(linux_nat_add_target): Register linux_nat_close and
	linux_nat_supports_multi_process.
	* linux-nat.h (iterate_over_lwps): Add filter argument.
	* linux-thread-db.c (thread_db_handle): Delete.
	(proc_handle, thread_agent, td_init_p, td_ta_new_p)
	(td_ta_map_id2thr_p, td_ta_map_lwp2thr_p, td_ta_thr_iter_p)
	(td_ta_event_addr_p, td_ta_set_event_p, td_ta_event_getmsg_p)
	(td_thr_validate_p, td_thr_get_info_p, td_thr_event_enable_p)
	(td_thr_tls_get_addr_p, td_create_bp_addr, td_death_bp_addr): No
	longer globals, moved to...
	(struct thread_db_info): ... this new structure.
	(thread_db_list): New.
	(add_thread_db_info, get_thread_db_info, delete_thread_db_info):
	New.
	(have_threads_callback): Filter out threads of all inferiors but
	the one specified by the ARGS argument.
	(have_threads): Add ptid argument specifying the inferior we're
	interested in.  Handle it.
	(struct thread_get_info_inout): New.
	(thread_get_info_callback, thread_from_lwp): Adjust to use it.
	(thread_db_attach_lwp): Check that inferior of the passed in
	thread is using thread-db.  Adjust.
	(enable_thread_event): Remove thread_agent parameter.  Instead,
	get it from the per-inferior thread-db info.
	(dladdr_to_soname): Move higher up.
	(enable_thread_event_reporting): Adjust to use per-inferior
	thread-db info.
	(try_thread_db_load_1): Replace `handle' parameter by a
	thread_db_info parameter.  Adjust to use per-inferior thread-db
	info.
	(try_thread_db_load): Adjust to use per-inferior thread-db info.
	(thread_db_load, disable_thread_event_reporting): Ditto.
	(check_for_thread_db): Remove conditional reporting of which
	libthread_db is in use.
	(thread_db_new_objfile): Add comment about inferior_ptid.
	(attach_thread): Adjust to use per-inferior thread-db info.
	(thread_db_detach): Adjust to use per-inferior thread-db info.
	Remove thread event breakpoints of the current inferior.  Only
	unpush the thread-db target if there are no more processes using
	it.
	(check_event): Adjust to use per-inferior thread-db info.
	(thread_db_wait): Adjust to use per-inferior thread-db info.  Only
	unpush the thread-db target if there are no more processes using
	it.
	(thread_db_mourn_inferior): Adjust to use per-inferior thread-db
	info.  Mark breakpoints of the current inferior out before
	deleting them.  Only unpush the thread-db target if there are no
	more processes using it.
	(find_new_threads_callback): Adjust to use per-inferior thread_db
	info.
	(thread_db_find_new_threads_1): Add new ptid argument.  Adjust to
	use per-inferior thread-db info.
	(thread_db_find_new_threads): Adjust to use per-inferior thread-db
	info.
	(thread_db_get_thread_local_address): Adjust.
	(thread_db_get_ada_task_ptid): Adjust.
	* inf-ptrace.c (inf_ptrace_mourn_inferior): Only unpush the target
	if there no more processes left to debug.
	* thread.c (set_running, set_executing): Handle resuming all
	threads of a single inferior.
	* mi/mi-interp.c (mi_output_running_pid): New.
	(mi_inferior_count): New.
	(mi_on_resume): For backwards compatibility, if resuming all
	threads of an inferior, and there is only one inferior, output
	"all".