Adding a SetRAILMode API.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index a2615fd90a9f3bc5289a769f474b4da3513d5058..f511a5803ac22766793f905a3ecd8bca1039c8d9 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -7686,6 +7686,11 @@ void Isolate::MemoryPressureNotification(MemoryPressureLevel level) {
                                                      Locker::IsLocked(this));
 }
 
+void Isolate::SetRAILMode(RAILMode rail_mode) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);
+  return isolate->SetRAILMode(rail_mode);
+}
+
 void Isolate::SetJitCodeEventHandler(JitCodeEventOptions options,
                                      JitCodeEventHandler event_handler) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(this);