[debugger] infrastructure for side-effect-free debug-evaluate.

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index 29a64d73cb5f86459b115bbaae7bf751cd8106e1..4e0187f3541b281bff8eb1818e3743a9f3985703 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -1041,6 +1041,8 @@ class ExternalReference BASE_EMBEDDED {
       Isolate* isolate);
 
   static ExternalReference debug_is_active_address(Isolate* isolate);
+  static ExternalReference debug_hook_on_function_call_address(
+      Isolate* isolate);
   static ExternalReference debug_after_break_target_address(Isolate* isolate);
 
   static ExternalReference is_profiling_address(Isolate* isolate);