Move at least one virtual method to our cpp files

Summary: Define at least one virtual method in a cpp file.

Differential Revision: D33891879

fbshipit-source-id: 3d2e3177b112c5fc7b2b84ed8bc41c5d0e15127e

folly/io/async/AsyncServerSocket.cpp

@@ -54,6 +54,8 @@ static constexpr bool msgErrQueueSupported =
     false;
 #endif // FOLLY_HAVE_MSG_ERRQUEUE
 
+AsyncServerSocket::AcceptCallback::~AcceptCallback() = default;
+
 const uint32_t AsyncServerSocket::kDefaultMaxAcceptAtOnce;
 const uint32_t AsyncServerSocket::kDefaultCallbackAcceptAtOnce;
 const uint32_t AsyncServerSocket::kDefaultMaxMessagesInQueue;

folly/io/async/AsyncServerSocket.h

@@ -144,7 +144,7 @@ class AsyncServerSocket : public DelayedDestruction, public AsyncSocketBase {
       std::chrono::steady_clock::time_point timeBeforeEnqueue;
     };
 
-    virtual ~AcceptCallback() = default;
+    virtual ~AcceptCallback();
 
     /**
      * connectionAccepted() is called whenever a new client connection is