[inspector] Initial import of v8_inspector.

src/inspector/Atomics.h

+// Copyright 2016 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.
+
+#ifndef V8_INSPECTOR_ATOMICS_H_
+#define V8_INSPECTOR_ATOMICS_H_
+
+#include <stdint.h>
+
+#if defined(_MSC_VER)
+#include <windows.h>
+#endif
+
+namespace v8_inspector {
+
+#if defined(_MSC_VER)
+
+inline int atomicIncrement(int volatile* addend) {
+  return InterlockedIncrement(reinterpret_cast<long volatile*>(addend));
+}
+
+#else
+
+inline int atomicAdd(int volatile* addend, int increment) {
+  return __sync_add_and_fetch(addend, increment);
+}
+inline int atomicIncrement(int volatile* addend) {
+  return atomicAdd(addend, 1);
+}
+
+#endif
+
+}  // namespace v8_inspector
+
+#endif  // V8_INSPECTOR_ATOMICS_H_