Add memory pressure interrupt for memory pressure notification

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index c51caf3212529b3a593b456dca8a88b436662f9f..4b44260eb6af116d81cd2b9b9063857fc1de933e 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -744,6 +744,8 @@ class Isolate {
   void RequestInterrupt(InterruptCallback callback, void* data);
   void InvokeApiInterruptCallbacks();
 
+  void RequestMemoryPressureInterrupt(v8::Isolate::MemoryPressureLevel level);
+
   // Administration
   void Iterate(ObjectVisitor* v);
   void Iterate(ObjectVisitor* v, ThreadLocalTop* t);
@@ -1344,6 +1346,8 @@ class Isolate {
   v8::Isolate::AbortOnUncaughtExceptionCallback
       abort_on_uncaught_exception_callback_;
 
+  v8::Isolate::MemoryPressureLevel memory_pressure_level_;
+
   friend class ExecutionAccess;
   friend class HandleScopeImplementer;
   friend class OptimizingCompileDispatcher;