Deoptimization can occur at Dart calls (includes native calls to C) but not at runtime calls. This …

runtime/vm/code_descriptors.cc

Index: runtime/vm/code_descriptors.cc
===================================================================
--- runtime/vm/code_descriptors.cc	(revision 11621)
+++ runtime/vm/code_descriptors.cc	(working copy)
@@ -15,21 +15,21 @@
   data.pc_offset = pc_offset;
   data.kind = kind;
   data.deopt_id = deopt_id;
-  data.token_index = token_index;
+  data.SetTokenPos(token_index);
   data.try_index = try_index;
   list_.Add(data);
 }
 
 
-void DescriptorList::AddDeoptInfo(intptr_t pc_offset,
-                                  intptr_t deopt_id,
-                                  intptr_t token_index,
-                                  intptr_t deopt_array_index) {
+void DescriptorList::AddDeoptIndex(intptr_t pc_offset,
+                                   intptr_t deopt_id,
+                                   DeoptReasonId deopt_reason,
+                                   intptr_t deopt_array_index) {
   struct PcDesc data;
   data.pc_offset = pc_offset;
   data.kind = PcDescriptors::kDeoptIndex;
   data.deopt_id = deopt_id;
-  data.token_index = token_index;
+  data.SetDeoptReason(deopt_reason);
   // Try_index is reused for deopt_array_index.
   data.try_index = deopt_array_index;
   list_.Add(data);