[vm/concurrency] When waking up ThreadInterrupter first check if it is shutdown already.

Fixes https://github.com/dart-lang/sdk/issues/42302

Change-Id: Ic250ce6d23d20d0435447c4e3ba546c1755c0458
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/151024
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Alexander Aprelev <aam@google.com>

runtime/vm/thread_interrupter.cc

@@ -146,6 +146,10 @@ void ThreadInterrupter::WakeUp() {
   }
   {
     MonitorLocker ml(monitor_);
+    if (shutdown_) {
+      // Late call
+      return;
+    }
     if (!initialized_) {
       // Early call.
       return;