Fix compilation on BSD platforms

src/libsampler/sampler.cc

 // 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.
 
 #include "src/libsampler/sampler.h"
 
 #if V8_OS_POSIX && !V8_OS_CYGWIN
 
 #define USE_SIGNALS
 
@@ skipping 175 matching lines @@
   bool is_success_;
 };
 
 // Returns key for hash map.
 void* ThreadKey(pthread_t thread_id) {
   return reinterpret_cast<void*>(thread_id);
 }
 
 // Returns hash value for hash map.
 uint32_t ThreadHash(pthread_t thread_id) {
-#if V8_OS_MACOSX
+#if V8_OS_BSD
   return static_cast<uint32_t>(reinterpret_cast<intptr_t>(thread_id));
 #else
   return static_cast<uint32_t>(thread_id);
 #endif
 }
 
 #endif  // USE_SIGNALS
 
 }  // namespace
 
@@ skipping 447 matching lines @@
 #endif
     SampleStack(state);
   }
   ResumeThread(profiled_thread);
 }
 
 #endif  // USE_SIGNALS
 
 }  // namespace sampler
 }  // namespace v8