LibCore: Expose TCPSocket file descriptor

Author: https://github.com/devgianlu
Commit: d6e9d2cdbb
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3571
Reviewed-by: https://github.com/ADKaster
Reviewed-by: https://github.com/alimpfard ✅

Libraries/LibCore/Socket.h

@@ -195,6 +195,8 @@ public:
     ErrorOr<void> set_blocking(bool enabled) override { return m_helper.set_blocking(enabled); }
     ErrorOr<void> set_close_on_exec(bool enabled) override { return m_helper.set_close_on_exec(enabled); }
 
+    int fd() const { return m_helper.fd(); }
+
     virtual ~TCPSocket() override { close(); }
 
 private: