[RFC/WIP PATCH 13/14] Make "thread apply all" only loop over threads in the current set

[Pedro Alves <pedro@codesourcery.com>]

This makes "thread apply all" only loop over threads in the current
set instead of always all threads.  That is,

  [all]> thread apply all printf "current thread is %d\n", $_thread

  Thread 3 (Thread 0x7ffff7028700 (LWP 30304)):
  current thread is 3

  Thread 2 (Thread 0x7ffff7829700 (LWP 30303)):
  current thread is 2

  Thread 1 (Thread 0x7ffff7fcb720 (LWP 30300)):
  current thread is 1

vs

  [all]> [1.1] thread apply all printf "current thread is %d\n", $_thread

  Thread 1 (Thread 0x7ffff7fcb720 (LWP 30300)):
  current thread is 1


I think it might make sense to make "info threads" only list threads
of the current focus too.  WDYT?
---
 gdb/thread.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/gdb/thread.c b/gdb/thread.c
index 846d2d3..55a64ac 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -46,6 +46,7 @@
 #include "gdb_regex.h"
 #include "cli/cli-utils.h"
 #include "continuations.h"
+#include "itset.h"
 
 /* Definition of struct thread_info exported to gdbthread.h.  */
 
@@ -1199,8 +1200,8 @@ thread_apply_all_command (char *cmd, int from_tty)
      execute_command.  */
   saved_cmd = xstrdup (cmd);
   make_cleanup (xfree, saved_cmd);
-  for (tp = thread_list; tp; tp = tp->next)
-    if (thread_alive (tp))
+  ALL_THREADS (tp)
+    if (itset_contains_thread (current_itset, tp) && thread_alive (tp))
       {
 	switch_to_thread (tp->ptid);