Delete redundant code in OptimizingCompileDispatcher::Stop

Removes job queue flushing in OptimizingCompileDispatcher::Stop when
FLAG_concurrent_recompilation_delay is set. Before this explicit
flushing was run, there was already a wait-loop which ensured the queue
was always empty.

Bug: v8:9810
Change-Id: I620bac9c9d73aead671b178c9450bdd25e6761b1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1934332
Commit-Queue: Dan Elphick <delphick@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Auto-Submit: Dan Elphick <delphick@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65154}

src/compiler-dispatcher/optimizing-compile-dispatcher.cc

@@ -193,14 +193,10 @@ void OptimizingCompileDispatcher::Stop() {
     mode_ = COMPILE;
   }
 
-  if (recompilation_delay_ != 0) {
   // At this point the optimizing compiler thread's event loop has stopped.
   // There is no need for a mutex when reading input_queue_length_.
-    while (input_queue_length_ > 0) CompileNext(NextInput());
-    InstallOptimizedFunctions();
-  } else {
+  DCHECK_EQ(input_queue_length_, 0);
   FlushOutputQueue(false);
-  }
 }
 
 void OptimizingCompileDispatcher::InstallOptimizedFunctions() {