Join threads after stopping.

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index fec3dc66ab4260b63b6e8a6023d34961e53536bc..b19cf40ef1de76f9d8b60a715085d8dfedea7bdc 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -1873,7 +1873,9 @@ void Isolate::Deinit() {
   if (state_ == INITIALIZED) {
     TRACE_ISOLATE(deinit);
 
-    if (FLAG_parallel_recompilation) optimizing_compiler_thread_.Stop();
+    if (FLAG_parallel_recompilation) {
+      optimizing_compiler_thread_.Stop();
+    }
 
     if (FLAG_sweeper_threads > 0) {
       for (int i = 0; i < FLAG_sweeper_threads; i++) {
@@ -1895,7 +1897,9 @@ void Isolate::Deinit() {
 
     // We must stop the logger before we tear down other components.
     Sampler* sampler = logger_->sampler();
-    if (sampler && sampler->IsActive()) sampler->Stop();
+    if (sampler && sampler->IsActive()) {
+      sampler->Stop();
+    }
 
     delete deoptimizer_data_;
     deoptimizer_data_ = NULL;