Restore back pointer from Instructions to Code

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 74013a6d5474f84e74143baf56aa710b0022a27f..47fa0092bddbe8913420aaaf15d9adfe8588b777 100644
--- a/runtime/vm/raw_object.cc
+++ b/runtime/vm/raw_object.cc
@@ -556,6 +556,9 @@ intptr_t RawObjectPool::VisitObjectPoolPointers(
 intptr_t RawInstructions::VisitInstructionsPointers(
     RawInstructions* raw_obj, ObjectPointerVisitor* visitor) {
   RawInstructions* obj = raw_obj->ptr();
+  if (!Dart::IsRunningPrecompiledCode()) {
+    visitor->VisitPointers(raw_obj->from(), raw_obj->to());
+  }
   return Instructions::InstanceSize(obj->size_);
 }