[esnext] prototype runtime implementation for async functions

src/profiler/sampler.h

Index: src/profiler/sampler.h
diff --git a/src/profiler/sampler.h b/src/profiler/sampler.h
index 04c8f0446cb940d1397e33e4247e87ad77759139..ee103674cc7b1b3e6947ed89a0e2c6c59d1bb9b8 100644
--- a/src/profiler/sampler.h
+++ b/src/profiler/sampler.h
@@ -140,7 +140,6 @@ class Sampler {
   DISALLOW_IMPLICIT_CONSTRUCTORS(Sampler);
 };
 
-
 #if defined(USE_SIMULATOR)
 class SimulatorHelper : AllStatic {
  public:
@@ -150,7 +149,6 @@ class SimulatorHelper : AllStatic {
 };
 #endif  // USE_SIMULATOR
 
-
 }  // namespace internal
 }  // namespace v8