Track JS allocations as they arrive with no affection on performance when tracking is switched off

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index d70d5aa928ba65810c67cd71c2d1c2a8db833d88..4c0134f1e55d93425eaf0d5295307349f9508103 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -734,6 +734,10 @@ class ExternalReference BASE_EMBEDDED {
 
   static ExternalReference get_make_code_young_function(Isolate* isolate);
 
+  // New heap objects tracking support.
+  static ExternalReference is_tracking_allocations_address(Isolate* isolate);
+  static ExternalReference record_object_allocation_function(Isolate* isolate);
+
   // Deoptimization support.
   static ExternalReference new_deoptimizer_function(Isolate* isolate);
   static ExternalReference compute_output_frames_function(Isolate* isolate);