expose AssertNoAllocation to api

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 6021 matching lines @@
   bool fits_into_int32_t = (value & (1 << 31)) == 0;
   if (fits_into_int32_t) {
     return Integer::New(static_cast<int32_t>(value), isolate);
   }
   ENTER_V8(internal_isolate);
   i::Handle<i::Object> result = internal_isolate->factory()->NewNumber(value);
   return Utils::IntegerToLocal(result);
 }
 
 
+#ifdef DEBUG
+v8::AssertNoGCScope::AssertNoGCScope(v8::Isolate* isolate)
+  : isolate_(isolate),
+    last_state_(i::EnterAllocationScope(
+        reinterpret_cast<i::Isolate*>(isolate), false)) {
+}
+
+v8::AssertNoGCScope::~AssertNoGCScope() {
+  i::ExitAllocationScope(reinterpret_cast<i::Isolate*>(isolate_), last_state_);
+}
+#endif
+
+
 void V8::IgnoreOutOfMemoryException() {
   EnterIsolateIfNeeded()->set_ignore_out_of_memory(true);
 }
 
 
 bool V8::AddMessageListener(MessageCallback that, Handle<Value> data) {
   i::Isolate* isolate = i::Isolate::Current();
   EnsureInitializedForIsolate(isolate, "v8::V8::AddMessageListener()");
   ON_BAILOUT(isolate, "v8::V8::AddMessageListener()", return false);
   ENTER_V8(isolate);
@@ skipping 1583 matching lines @@
 
   v->VisitPointers(blocks_.first(), first_block_limit_);
 
   for (int i = 1; i < blocks_.length(); i++) {
     v->VisitPointers(blocks_[i], &blocks_[i][kHandleBlockSize]);
   }
 }
 
 
 } }  // namespace v8::internal