Introduce API to temporarily interrupt long running JavaScript code.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 562985cc8ba1e700c6f4153c951fec2be8f73b57..cefc138f276855702c8ab19df7ee63370b2a4bb9 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -6722,6 +6722,17 @@ void V8::CancelTerminateExecution(Isolate* isolate) {
 }
 
 
+void Isolate::RequestInterrupt(InterruptCallback callback, void* data) {
+  reinterpret_cast<i::Isolate*>(this)->stack_guard()->RequestInterrupt(
+      callback, data);
+}
+
+
+void Isolate::ClearInterrupt() {
+  reinterpret_cast<i::Isolate*>(this)->stack_guard()->ClearInterrupt();
+}
+
+
 Isolate* Isolate::GetCurrent() {
   i::Isolate* isolate = i::Isolate::UncheckedCurrent();
   return reinterpret_cast<Isolate*>(isolate);