Make maps in monomorphic IC stubs weak.

src/objects-visiting.h

Index: src/objects-visiting.h
diff --git a/src/objects-visiting.h b/src/objects-visiting.h
index de8ca6d055d4d2673b968e669169a108dd5ebc64..63c75a2299bc1be3a6a7bbf0e186b85f6d31414e 100644
--- a/src/objects-visiting.h
+++ b/src/objects-visiting.h
@@ -483,6 +483,15 @@ VisitorDispatchTable<typename StaticMarkingVisitor<StaticVisitor>::Callback>
     StaticMarkingVisitor<StaticVisitor>::table_;
 
 
+class WeakObjectRetainer;
+
+
+template <class T>
+Object* VisitWeakList(Heap* heap,

[Michael Starzinger, 2014/04/11 09:01:56]

suggestion: As discussed offline, I know you only moved this function and didn't
change it, but a few lines of comments describing it here would be nice. :)

[ulan, 2014/04/11 09:28:01]

Added this comment:

A weak list is single linked list where each element has a weak pointer to the
next element. Given the head of the list, this function removes dead elements
from the list and if requested records slots for next-element pointers. The
template parameter T is a WeakListVisitor that defines how to access the
next-element pointers.

+                      Object* list,
+                      WeakObjectRetainer* retainer,
+                      bool record_slots);
+
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_VISITING_H_