AOT: Add a separate switchable call state for unlinked calls.

runtime/vm/raw_object.cc

Index: runtime/vm/raw_object.cc
diff --git a/runtime/vm/raw_object.cc b/runtime/vm/raw_object.cc
index 991b2e0f254940cf0e0606fa3fb0de4f63e259d9..d777f68b57d2426a166f82c5b06bb458f8640c1c 100644
--- a/runtime/vm/raw_object.cc
+++ b/runtime/vm/raw_object.cc
@@ -646,6 +646,13 @@ intptr_t RawSingleTargetCache::VisitSingleTargetCachePointers(
 }
 
 
+intptr_t RawUnlinkedCall::VisitUnlinkedCallPointers(
+    RawUnlinkedCall* raw_obj, ObjectPointerVisitor* visitor) {
+  visitor->VisitPointers(raw_obj->from(), raw_obj->to());
+  return UnlinkedCall::InstanceSize();
+}
+
+
 intptr_t RawICData::VisitICDataPointers(RawICData* raw_obj,
                                         ObjectPointerVisitor* visitor) {
   visitor->VisitPointers(raw_obj->from(), raw_obj->to());