AllocationSite objects weakly linked for traversal

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index ab51b9118a3d3815bddd9af5d5798a8299483284..e52dfff2ff6bc989703ec267ab8471809020bfbf 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -2603,6 +2603,16 @@ void LCodeGen::DoStoreGlobalGeneric(LStoreGlobalGeneric* instr) {
 }
 
 
+void LCodeGen::DoLinkObjectInList(LLinkObjectInList* instr) {
+  Register object = ToRegister(instr->object());
+  ExternalReference sites_list_address = instr->GetReference(isolate());
+  __ Load(kScratchRegister, sites_list_address);
+  __ movq(FieldOperand(object, instr->hydrogen()->store_field().offset()),
+          kScratchRegister);
+  __ Store(sites_list_address, object);
+}
+
+
 void LCodeGen::DoLoadContextSlot(LLoadContextSlot* instr) {
   Register context = ToRegister(instr->context());
   Register result = ToRegister(instr->result());