[api] Add a switch that controls if ES2015 tail call elimination feature is enabled or not.

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 8071 matching lines @@
 Local<Context> Debug::GetDebugContext() {
   return GetDebugContext(reinterpret_cast<Isolate*>(i::Isolate::Current()));
 }
 
 
 void Debug::SetLiveEditEnabled(Isolate* isolate, bool enable) {
   i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(isolate);
   internal_isolate->debug()->set_live_edit_enabled(enable);
 }
 
+bool Debug::IsTailCallEliminationEnabled(Isolate* isolate) {
+  i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  return internal_isolate->is_tail_call_elimination_enabled();
+}
+
+void Debug::SetTailCallEliminationEnabled(Isolate* isolate, bool enabled) {
+  i::Isolate* internal_isolate = reinterpret_cast<i::Isolate*>(isolate);
+  internal_isolate->SetTailCallEliminationEnabled(enabled);
+}
 
 MaybeLocal<Array> Debug::GetInternalProperties(Isolate* v8_isolate,
                                                Local<Value> value) {
   i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
   ENTER_V8(isolate);
   i::Handle<i::Object> val = Utils::OpenHandle(*value);
   i::Handle<i::JSArray> result;
   if (!i::Runtime::GetInternalProperties(isolate, val).ToHandle(&result))
     return MaybeLocal<Array>();
   return Utils::ToLocal(result);
@@ skipping 659 matching lines @@
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 }  // namespace internal
 }  // namespace v8