* linux-nat.c (linux_nat_attach): Add the pid we attached to, to

	* linux-nat.c (linux_nat_attach): Add the pid we attached to, to
	gdb's thread list.
	(linux_nat_wait): Add main lwp to gdb's thread list.
	* linux-thread-db.c (find_new_threads_callback): Also attach to
	already listed threads which thread_db didn't know about yet.