* inf-ttrace.c: Include "gdbthread.h".

* inf-ttrace.c: Include "gdbthread.h".
(inf_ttrace_num_lwps): New variable.
(inf_ttrace_num_lwps_in_syscall): Renamed from
inf_ttrace_num_threads_in_syscall.
(inf_ttrace_him): Track TTEVT_LWP_CREATE, TTEVT_LWP_EXIT and
TTEVT_LWP_TERMINATE events.
(inf_ttrace_create_inferior): Assert that INF_TTRACE_NUM_LWPS is
zero.
(inf_ttrace_mourn_inferior): Set INF_TTRACE_NUM_LWPS to zero.
(inf_ttrace_attach): Assert that INF_TTRACE_NUM_LWPS is zero.
Track TTEVT_LWP_CREATE, TTEVT_LWP_EXIT and TTEVT_LWP_TERMINATE
events.
(inf_ttrace_wait): Report status as TARGET_WAITKIND_SPURIOUS by
default.  Handle TTEVT_LWP_CREATE, TTEVT_LWP_EXIT and
TTEVT_LWP_TERMINATE events.
(inf_ttrace_thread_alive, inf_ttrace_pid_to_str): New functions.
(inf_ttrace_target): Set to_thread_alive and to_pid_to_str.
* Makefile.in (inf-ttrace.o): Update dependencies.