Xtensa ESP32: Corrects a problem with dispatching to signal handlers: Cannot...

Xtensa ESP32:  Corrects a problem with dispatching to signal handlers:  Cannot vector directly to the signal handling function as in other ABIs under the Xtensa Window ABI.  In that case, we need to go through a tiny hook when performs the correct window call (call4) otherwise registers will be scrambled in the signal handler