Use boost:has_trivial_destructor instead of std::...

Summary: Boost's version is 4.8 safe.  std's version changes name

Test Plan: hhvm builds

Reviewed By: andrei.alexandrescu@fb.com

FB internal diff: D883508

folly/ProducerConsumerQueue.h

@@ -59,7 +59,7 @@ struct ProducerConsumerQueue : private boost::noncopyable {
     // We need to destruct anything that may still exist in our queue.
     // (No real synchronization needed at destructor time: only one
     // thread can be doing this.)
-    if (!std::has_trivial_destructor<T>::value) {
+    if (!boost::has_trivial_destructor<T>::value) {
       int read = readIndex_;
       int end = writeIndex_;
       while (read != end) {