Fix compilation on BSD platforms

src/libsampler/sampler.cc

Index: src/libsampler/sampler.cc
diff --git a/src/libsampler/sampler.cc b/src/libsampler/sampler.cc
index b4d82f13855a038dfdb424ca5dd92c9f26e44f3f..71c667f4d6675ce675cc62aa6b32d8a0d6ef6295 100644
--- a/src/libsampler/sampler.cc
+++ b/src/libsampler/sampler.cc
@@ -193,7 +193,7 @@ void* ThreadKey(pthread_t 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);