Reland "Flush parallel recompilation queues on context dispose notification."

src/debug.cc

Index: src/debug.cc
diff --git a/src/debug.cc b/src/debug.cc
index 04f8a7a0274eeaec9d401bc436aad178a182739f..845443881557077eb6c2112cef5addb1a4ebaffd 100644
--- a/src/debug.cc
+++ b/src/debug.cc
@@ -2044,6 +2044,10 @@ void Debug::PrepareForBreakPoints() {
   // If preparing for the first break point make sure to deoptimize all
   // functions as debugging does not work with optimized code.
   if (!has_break_points_) {
+    if (FLAG_parallel_recompilation) {
+      isolate_->optimizing_compiler_thread()->Flush();
+    }
+
     Deoptimizer::DeoptimizeAll(isolate_);
 
     Handle<Code> lazy_compile =