MINOR: debug: report the group and thread ID in the thread dumps

Now thread dumps will report the thread group number and the ID within
this group. Note that this is still quite limited because some masks
are calculated based on the thread in argument while they have to be
performed against a group-level thread ID.
diff --git a/src/debug.c b/src/debug.c
index b1472ae..0561992 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -156,7 +156,7 @@
 
 	chunk_appendf(buf,
 	              "%c%cThread %-2u: id=0x%llx act=%d glob=%d wq=%d rq=%d tl=%d tlsz=%d rqsz=%d\n"
-	              "             stuck=%d prof=%d",
+	              "     %2u/%-2u   stuck=%d prof=%d",
 	              (thr == calling_tid) ? '*' : ' ', stuck ? '>' : ' ', thr + 1,
 		      ha_get_pthread_id(thr),
 		      thread_has_tasks(),
@@ -169,6 +169,7 @@
 			MT_LIST_ISEMPTY(&ha_thread_ctx[thr].shared_tasklet_list)),
 	              ha_thread_ctx[thr].tasks_in_list,
 	              ha_thread_ctx[thr].rq_total,
+		      ha_thread_info[thr].tg->tgid, ha_thread_info[thr].ltid + 1,
 	              stuck,
 	              !!(task_profiling_mask & thr_bit));
 
@@ -180,7 +181,7 @@
 	chunk_appendf(buf, "\n");
 	chunk_appendf(buf, "             cpu_ns: poll=%llu now=%llu diff=%llu\n", p, n, n-p);
 
-	/* this is the end of what we can dump from outside the thread */
+	/* this is the end of what we can dump from outside the current thread */
 
 	if (thr != tid)
 		return;