Merge flush code phase into marking phase.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 9596a6a23dc09e368b193ba0bb9849bccb3b6553..f2894db36475adccf465352249bad93da830f51b 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -1258,10 +1258,6 @@ class Heap : public AllStatic {
   // Flush the number to string cache.
   static void FlushNumberStringCache();
 
-  // Flush code from functions we do not expect to use again. The code will
-  // be replaced with a lazy compilable version.
-  static void FlushCode();
-
   static void UpdateSurvivalRateTrend(int start_new_space_size);
 
   enum SurvivalRateTrend { INCREASING, STABLE, DECREASING, FLUCTUATING };