Make the code flushing candidate field explicit in code objects.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index 64489a1cce1ff8a5ee6d9228fa3adbee7082f961..1f11f5aac20f32dbb78c4499def247f8f1f5405d 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -2799,6 +2799,7 @@ MaybeObject* Heap::CreateCode(const CodeDesc& desc,
     code->set_check_type(RECEIVER_MAP_CHECK);
   }
   code->set_deoptimization_data(empty_fixed_array());
+  code->set_next_code_flushing_candidate(undefined_value());
   // Allow self references to created code object by patching the handle to
   // point to the newly allocated Code object.
   if (!self_reference.is_null()) {