Initial SIMDBC interpreter.

runtime/vm/atomic_simulator.h

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_ATOMIC_SIMULATOR_H_
 #define VM_ATOMIC_SIMULATOR_H_
 
 #if !defined VM_ATOMIC_H_
 #error Do not include atomic_simulator.h directly. Use atomic.h instead.
 #endif
 
 namespace dart {
 
-#if defined(USING_SIMULATOR)
+#if defined(USING_SIMULATOR_ATOMICS)
 // Forward atomic operations to the simulator if the simulator is active.
 inline uword AtomicOperations::CompareAndSwapWord(uword* ptr,
                                                   uword old_value,
                                                   uword new_value) {
   return Simulator::CompareExchange(ptr, old_value, new_value);
 }
 
 
 inline uint32_t AtomicOperations::CompareAndSwapUint32(uint32_t* ptr,
                                                        uint32_t old_value,
                                                        uint32_t new_value) {
   return Simulator::CompareExchangeUint32(ptr, old_value, new_value);
 }
-#endif  // defined(USING_SIMULATOR)
+#endif  // defined(USING_SIMULATOR_ATOMICS)
 
 }  // namespace dart
 
 #endif  // VM_ATOMIC_SIMULATOR_H_