Remove more feature in product mode

runtime/vm/thread_interrupter_android.cc

Index: runtime/vm/thread_interrupter_android.cc
diff --git a/runtime/vm/thread_interrupter_android.cc b/runtime/vm/thread_interrupter_android.cc
index 665677579d5b357fe0a661a15ffb9c87030b193f..82be148cbd07f3b85c7f594eaf585ef9b832ca6b 100644
--- a/runtime/vm/thread_interrupter_android.cc
+++ b/runtime/vm/thread_interrupter_android.cc
@@ -16,6 +16,8 @@
 
 namespace dart {
 
+#ifndef PRODUCT
+
 DECLARE_FLAG(bool, thread_interrupter);
 DECLARE_FLAG(bool, trace_thread_interrupter);
 
@@ -64,6 +66,8 @@ void ThreadInterrupter::RemoveSignalHandler() {
   SignalHandler::Remove();
 }
 
+#endif  // !PRODUCT
+
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_ANDROID)