Minor cleanup (no functional change): rename 'struct _Thr :: opaque'
to 'hgthread', since that's what it is really.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@11619 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/helgrind/hg_lock_n_thread.h b/helgrind/hg_lock_n_thread.h
index 78948fe..e109b55 100644
--- a/helgrind/hg_lock_n_thread.h
+++ b/helgrind/hg_lock_n_thread.h
@@ -83,8 +83,8 @@
       /* ADMIN */
       struct _Thread* admin;
       UInt            magic;
-      Thr*            hbthr;
-      ThreadId        coretid;
+      Thr*            hbthr; /* which in turn points back here .. */
+      ThreadId        coretid;  /* .. via its hgthread field */
       /* USEFUL */
       WordSetID locksetA; /* WordSet of Lock* currently held by thread */
       WordSetID locksetW; /* subset of locksetA held in w-mode */