Implement OS::ReleaseStore for Solaris

src/platform-freebsd.cc

Index: src/platform-freebsd.cc
diff --git a/src/platform-freebsd.cc b/src/platform-freebsd.cc
index 72fe088d8ad6baec3cad1e5271358e9fa010a761..9b8b20675f064698f8ab0abdcac43307a952a166 100644
--- a/src/platform-freebsd.cc
+++ b/src/platform-freebsd.cc
@@ -84,6 +84,12 @@ void OS::Setup() {
 }
 
 
+void OS::ReleaseStore(volatile AtomicWord* ptr, AtomicWord value) {
+  __asm__ __volatile__("" : : : "memory");
+  *ptr = value;
+}
+
+
 uint64_t OS::CpuFeaturesImpliedByPlatform() {
   return 0;  // FreeBSD runs on anything.
 }