Move PromiseNextMicrotaskID to cpp

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index a1e16925341358b09813f94c9e69a6e8cbcba219..0b9ea7bed1d4cdce411f53cc0c394ce6481c65bb 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -403,6 +403,7 @@ typedef List<HeapObject*> DebugObjectCache;
   V(base::HashMap*, external_reference_map, nullptr)                          \
   V(base::HashMap*, root_index_map, nullptr)                                  \
   V(int, pending_microtask_count, 0)                                          \
+  V(int, debug_microtask_count, 0)                                            \
   V(HStatistics*, hstatistics, nullptr)                                       \
   V(CompilationStatistics*, turbo_statistics, nullptr)                        \
   V(HTracer*, htracer, nullptr)                                               \
@@ -1104,6 +1105,7 @@ class Isolate {
   void EnqueueMicrotask(Handle<Object> microtask);
   void RunMicrotasks();
   bool IsRunningMicrotasks() const { return is_running_microtasks_; }
+  int GetNextDebugMicrotaskId() { return debug_microtask_count_++; }
 
   void SetUseCounterCallback(v8::Isolate::UseCounterCallback callback);
   void CountUsage(v8::Isolate::UseCounterFeature feature);