Make maps in monomorphic IC stubs weak.

src/mark-compact.h

Index: src/mark-compact.h
diff --git a/src/mark-compact.h b/src/mark-compact.h
index 0ebe8a0f747846193bfd0002cccd8bec247df4a0..6a98a394a2101615ee06d63f9c1f847fa2370f34 100644
--- a/src/mark-compact.h
+++ b/src/mark-compact.h
@@ -638,7 +638,7 @@ class MarkCompactCollector {
   void VerifyMarkbitsAreClean();
   static void VerifyMarkbitsAreClean(PagedSpace* space);
   static void VerifyMarkbitsAreClean(NewSpace* space);
-  void VerifyWeakEmbeddedObjectsInOptimizedCode();
+  void VerifyWeakEmbeddedObjectsInCode();
   void VerifyOmittedMapChecks();
 #endif
 
@@ -899,8 +899,11 @@ class MarkCompactCollector {
   void ClearNonLivePrototypeTransitions(Map* map);
   void ClearNonLiveMapTransitions(Map* map, MarkBit map_mark);
 
-  void ClearAndDeoptimizeDependentCode(DependentCode* dependent_code);
+  void ClearDependentCode(DependentCode* dependent_code);
+  void ClearDependentICList(Object* head);
   void ClearNonLiveDependentCode(DependentCode* dependent_code);
+  int ClearNonLiveDependentCodeInGroup(DependentCode* dependent_code, int group,
+                                       int start, int end, int new_start);
 
   // Marking detaches initial maps from SharedFunctionInfo objects
   // to make this reference weak. We need to reattach initial maps