Use WeakCells in the optimized code map rather than traversing in pause.

src/heap/mark-compact.h

Index: src/heap/mark-compact.h
diff --git a/src/heap/mark-compact.h b/src/heap/mark-compact.h
index 25f09a7be1db1e286b5b7d20bea95819d50ebccd..91fcc20b13e5b4bbd2686e1160dc6510115faceb 100644
--- a/src/heap/mark-compact.h
+++ b/src/heap/mark-compact.h
@@ -680,11 +680,6 @@ class MarkCompactCollector {
   void ProcessAndClearTransitionArrays();
   void AbortTransitionArrays();
 
-  // After all reachable objects have been marked, those entries within
-  // optimized code maps that became unreachable are removed, potentially
-  // trimming or clearing out the entire optimized code map.
-  void ProcessAndClearOptimizedCodeMaps();
-
   // Process non-live references in maps and optimized code.
   void ProcessWeakReferences();