AllocationSite objects weakly linked for traversal

src/arm/lithium-arm.cc

Index: src/arm/lithium-arm.cc
diff --git a/src/arm/lithium-arm.cc b/src/arm/lithium-arm.cc
index d614bd026205190206c640b2e2637e691e10b31c..b68d22f33607aaf1e75d97b9278823d6b795e91d 100644
--- a/src/arm/lithium-arm.cc
+++ b/src/arm/lithium-arm.cc
@@ -272,6 +272,24 @@ void LCallConstantFunction::PrintDataTo(StringStream* stream) {
 }
 
 
+ExternalReference LLinkObjectInList::GetReference(Isolate* isolate) {
+  switch (hydrogen()->known_list()) {
+    case HLinkObjectInList::ALLOCATION_SITE_LIST:
+      return ExternalReference::allocation_sites_list_address(isolate);
+  }
+
+  UNREACHABLE();
+  // Return a dummy value
+  return ExternalReference::isolate_address(isolate);
+}
+
+
+void LLinkObjectInList::PrintDataTo(StringStream* stream) {
+  object()->PrintTo(stream);
+  stream->Add(" offset %d", hydrogen()->store_field().offset());
+}
+
+
 void LLoadContextSlot::PrintDataTo(StringStream* stream) {
   context()->PrintTo(stream);
   stream->Add("[%d]", slot_index());
@@ -2113,6 +2131,13 @@ LInstruction* LChunkBuilder::DoStoreGlobalGeneric(HStoreGlobalGeneric* instr) {
 }
 
 
+LInstruction* LChunkBuilder::DoLinkObjectInList(HLinkObjectInList* instr) {
+  LOperand* object = UseRegister(instr->value());
+  LLinkObjectInList* result = new(zone()) LLinkObjectInList(object);
+  return result;
+}
+
+
 LInstruction* LChunkBuilder::DoLoadContextSlot(HLoadContextSlot* instr) {
   LOperand* context = UseRegisterAtStart(instr->value());
   LInstruction* result =