atomic static_assert failed under MacOS Serria with CUDA

[gangliao]

// This implementation is transitional and maintains the original API for
// atomicops.h. This requires casting memory locations to the atomic types, and
// assumes that the API and the C++11 implementation are layout-compatible,
// which isn't true for all implementations or hardware platforms. The static
// assertion should detect this issue, were it to fire then this header
// shouldn't be used.
//
// TODO(jfb) If this header manages to stay committed then the API should be
//           modified, and all call sites updated.
typedef volatile std::atomic<Atomic32>* AtomicLocation32;
// static_assert(sizeof(*(AtomicLocation32) nullptr) == sizeof(Atomic32),
//              "incompatible 32-bit atomic layout");

[TeBoring]

Seems to be fixed by tensorflow/tensorflow#7364. Feel free to reopen it if it's not fixed.