Partially implement DBC profiler.

runtime/vm/thread.h

Index: runtime/vm/thread.h
diff --git a/runtime/vm/thread.h b/runtime/vm/thread.h
index 2e56a8e672b64d1036082c0fc74d0b5ade713320..6805ada1b8ce013bbbc0b634d852f6107bca2a8f 100644
--- a/runtime/vm/thread.h
+++ b/runtime/vm/thread.h
@@ -329,6 +329,9 @@ class Thread : public BaseThread {
   uword top_exit_frame_info() const {
     return top_exit_frame_info_;
   }
+  void set_top_exit_frame_info(uword top_exit_frame_info) {
+    top_exit_frame_info_ = top_exit_frame_info;
+  }
   static intptr_t top_exit_frame_info_offset() {
     return OFFSET_OF(Thread, top_exit_frame_info_);
   }
@@ -727,10 +730,6 @@ LEAF_RUNTIME_ENTRY_LIST(DECLARE_MEMBERS)
     zone_ = zone;
   }
 
-  void set_top_exit_frame_info(uword top_exit_frame_info) {
-    top_exit_frame_info_ = top_exit_frame_info;
-  }
-
   void set_safepoint_state(uint32_t value) {
     safepoint_state_ = value;
   }