Perform full gcs when context disposals happen too frequent.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index bd49c84630b23748a747c13a867ef04d15ad5ee4..60c6b3c727a2c797195fde255e8e76ee142835d6 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -6724,9 +6724,9 @@ void v8::Isolate::LowMemoryNotification() {
 }
 
 
-int v8::Isolate::ContextDisposedNotification() {
+void v8::Isolate::ContextDisposedNotification() {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
-  return isolate->heap()->NotifyContextDisposed();
+  isolate->heap()->NotifyContextDisposed();
 }