* sigproc.cc (sig_hold): Delete.
(sigheld): Delete.
(sig_send): Eliminate special-case __SIGHOLD handling.
(wait_sig): Just flag when signals are on hold and add them to the queue rather
than stalling the wait_sig loop.  Clear the flag when __SIGNOHOLD is specified.
	* libc/reent/reent.c (_wrapup_reent): Remove.