coregrind/m_scheduler: Inform tools about thread ID while translating

This patch fixes the following assertion failure in DRD with
ENABLE_DRD_CONSISTENCY_CHECKS defined:

drd: drd_load_store.c:186 (vgDrd_trace_load): the 'impossible' happened.
==9543==    at 0x2803C4EC: report_and_quit (m_libcassert.c:279)
==9543==    by 0x2803C646: vgPlain_assert_fail (m_libcassert.c:359)
==9543==    by 0x2802A488: vgDrd_trace_load (drd_load_store.c:186)
==9543==    by 0x2805743E: vgPlain_translate (m_translate.c:1403)
==9543==    by 0x28088FCE: vgPlain_scheduler (scheduler.c:1014)
==9543==    by 0x280983D2: run_a_thread_NORETURN (syswrap-linux.c:103)


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13862 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/coregrind/m_scheduler/scheduler.c b/coregrind/m_scheduler/scheduler.c
index 52b4d0f..b6f558d 100644
--- a/coregrind/m_scheduler/scheduler.c
+++ b/coregrind/m_scheduler/scheduler.c
@@ -1011,6 +1011,7 @@
                                  ip, True/*upd_fast_cache*/ );
    if (UNLIKELY(!found)) {
       /* Not found; we need to request a translation. */
+      VG_TRACK( start_client_code, tid, bbs_done );
       if (VG_(translate)( tid, ip, /*debug*/False, 0/*not verbose*/, 
                           bbs_done, True/*allow redirection*/ )) {
          found = VG_(search_transtab)( NULL, NULL, NULL,
@@ -1024,6 +1025,7 @@
 	 // or the thread has been marked for termination.  Either
 	 // way, we just need to go back into the scheduler loop.
       }
+      VG_TRACK( stop_client_code, tid, bbs_done );
    }
 }