The reason for the error is missing definition for SIGNAL_WITH_IO_CLOSE on this platform
which now needs to  always be defined, as in 5.6

On Solaris10 only, this preprocessor constant was not defined,  thus code that shutdowns a socket in THD::awake was not executed, and polling thread was not interrupted.

Fix is to always define SIGNAL_WITH_IO_CLOSE, just like MySQL5.6 does.