[Interpreter] Enable tracing of bytecode handler dispatches.

src/assembler.cc

Index: src/assembler.cc
diff --git a/src/assembler.cc b/src/assembler.cc
index 0ca865bdd0f4a552f693cf67b38879940c807b18..5aa39b303df3862518d9d7dd7fba3c7e9d5b233d 100644
--- a/src/assembler.cc
+++ b/src/assembler.cc
@@ -1072,6 +1072,13 @@ ExternalReference ExternalReference::interpreter_dispatch_table_address(
   return ExternalReference(isolate->interpreter()->dispatch_table_address());
 }
 
+ExternalReference
+ExternalReference::interpreter_handler_to_handler_dispatch_counters(
+    Isolate* isolate) {
+  return ExternalReference(
+      isolate->interpreter()->handler_to_handler_dispatch_counters());
+}
+
 ExternalReference::ExternalReference(StatsCounter* counter)
   : address_(reinterpret_cast<Address>(counter->GetInternalPointer())) {}