Check in hello world example so it stays up to date

samples/hello-world.cc

+// Copyright 2015 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "include/libplatform/libplatform.h"
+#include "include/v8.h"
+
+using namespace v8;
+
+class ArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
+ public:
+  virtual void* Allocate(size_t length) {
+    void* data = AllocateUninitialized(length);
+    return data == NULL ? data : memset(data, 0, length);
+  }
+  virtual void* AllocateUninitialized(size_t length) { return malloc(length); }
+  virtual void Free(void* data, size_t) { free(data); }
+};
+
+
+int main(int argc, char* argv[]) {
+  // Initialize V8.
+  V8::InitializeICU();
+  Platform* platform = platform::CreateDefaultPlatform();
+  V8::InitializePlatform(platform);
+  V8::Initialize();
+
+  // Create a new Isolate and make it the current one.
+  ArrayBufferAllocator allocator;
+  Isolate::CreateParams create_params;
+  create_params.array_buffer_allocator = &allocator;
+  Isolate* isolate = Isolate::New(create_params);
+  {
+    Isolate::Scope isolate_scope(isolate);
+
+    // Create a stack-allocated handle scope.
+    HandleScope handle_scope(isolate);
+
+    // Create a new context.
+    Local<Context> context = Context::New(isolate);
+
+    // Enter the context for compiling and running the hello world script.
+    Context::Scope context_scope(context);
+
+    // Create a string containing the JavaScript source code.
+    Local<String> source = String::NewFromUtf8(isolate, "'Hello' + ', World!'");
+
+    // Compile the source code.
+    Local<Script> script = Script::Compile(source);
+
+    // Run the script to get the result.
+    Local<Value> result = script->Run();
+
+    // Convert the result to an UTF8 string and print it.
+    String::Utf8Value utf8(result);
+    printf("%s\n", *utf8);
+  }
+
+  // Dispose the isolate and tear down V8.
+  isolate->Dispose();
+  V8::Dispose();
+  V8::ShutdownPlatform();
+  delete platform;
+  return 0;
+}