VM: Fix memory leak during shutdown

runtime/bin/socket.h

Index: runtime/bin/socket.h
diff --git a/runtime/bin/socket.h b/runtime/bin/socket.h
index 35d4acc870fa911e906958468097a506a7a5c2b6..d8f9e0126e40927a9819c8f736c0ad83ddb8d939 100644
--- a/runtime/bin/socket.h
+++ b/runtime/bin/socket.h
@@ -467,9 +467,12 @@ class ListeningSocketRegistry {
 
   OSSocket* LookupByFd(intptr_t fd);
   void InsertByFd(intptr_t fd, OSSocket* socket);
-  void RemoveByFd(intptr_t fd);
 
-  bool CloseOneSafe(OSSocket* os_socket);
+  // If `map_cursor` is provided it will be updated to point to the next
+  // element (in iteration order of `sockets_by_fd`) after `fd` was removed.
+  void RemoveByFd(intptr_t fd, HashMap::Entry** map_cursor);
+
+  bool CloseOneSafe(OSSocket* os_socket, HashMap::Entry** fd_map_cursor);
   void CloseAllSafe();
 
   HashMap sockets_by_port_;