Re-reland "Flush parallel recompilation queues on context dispose notification"

src/optimizing-compiler-thread.h

Index: src/optimizing-compiler-thread.h
diff --git a/src/optimizing-compiler-thread.h b/src/optimizing-compiler-thread.h
index 275ceb40b711ccecf4ee4937355fed1eb8f23c61..5a87a975e5dfe4572279927c79aa7b9152e6b2b5 100644
--- a/src/optimizing-compiler-thread.h
+++ b/src/optimizing-compiler-thread.h
@@ -54,13 +54,13 @@ class OptimizingCompilerThread : public Thread {
       install_mutex_(OS::CreateMutex()),
       time_spent_compiling_(0),
       time_spent_total_(0) {
-    NoBarrier_Store(&stop_thread_, static_cast<AtomicWord>(false));
+    NoBarrier_Store(&stop_thread_, static_cast<AtomicWord>(CONTINUE));
     NoBarrier_Store(&queue_length_, static_cast<AtomicWord>(0));
   }
 
   void Run();
   void Stop();
-  void CompileNext();
+  void Flush();
   void QueueForOptimization(OptimizingCompiler* optimizing_compiler);
   void InstallOptimizedFunctions();
 
@@ -92,6 +92,12 @@ class OptimizingCompilerThread : public Thread {
   }
 
  private:
+  enum StopFlag { CONTINUE, STOP, FLUSH };
+
+  void FlushQueue(UnboundQueue<OptimizingCompiler*>* queue,
+                  bool restore_function_code);
+  void CompileNext();
+
 #ifdef DEBUG
   int thread_id_;
   Mutex* thread_id_mutex_;