* debug.h: Add regparm attributes to some functions.

* debug.h: Add regparm attributes to some functions.
* signal.cc (sigaction): Don't treat SIGCONT specially.
* exceptions.cc (interrupt_setup): Save sa_flags of interrupted signal for
later use.
(sig_handler): Default any stopping signal to SIGSTOP.
(call_signal_handler): New function.
(sigdelayed0): New function.
* sigproc.cc (sigproc_init): Initialize SIGSTOP sigaction for special behavior.
* sigproc.h: Define call_signal_handler.
* syscalls.cc (_read): Allow restartable signal behavior.